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Vulnerabilidades publicadas, com severidade, exploração conhecida e fontes oficiais.
CVE-2026-46107
Alta · 7.8
CWE-191 28/05/2026
dm-thin: fix metadata refcount underflow
In the Linux kernel, the following vulnerability has been resolved:
dm-thin: fix metadata refcount underflow
There's a bug in dm-thin in the function rebalance_children. If the
internal btree node has one entry, the code tries to copy all btree
entries from the node's child to the node itself and then decrement the
child's reference count.
If the child node is shared (it has reference count > 1), we won't free
it, so there would be two pointers to each of the grandchildren nodes.
But the reference counts of the grandchildren is not increased, thus the
reference count doesn't match the number of pointers that point to the
grandchildren. This results in "device mapper: space map common: unable
to decrement block" errors.
Fix this bug by incrementing reference counts on the grandchildren if the
btree node is shared.
CVE-2026-45999
Alta · 7.1
CWE-191 27/05/2026
erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()
In the Linux kernel, the following vulnerability has been resolved:
erofs: fix unsigned underflow in z_erofs_lz4_handle_overlap()
Some crafted images can have illegal (!partial_decoding &&
m_llen < m_plen) extents, and the LZ4 inplace decompression path
can be wrongly hit, but it cannot handle (outpages < inpages)
properly: "outpages - inpages" wraps to a large value and
the subsequent rq->out[] access reads past the decompressed_pages
array.
However, such crafted cases can correctly result in a corruption
report in the normal LZ4 non-inplace path.
Let's add an additional check to fix this for backporting.
Reproducible image (base64-encoded gzipped blob):
H4sIAJGR12kCA+3SPUoDQRgG4MkmkkZk8QRbRFIIi9hbpEjrHQI5ghfwCN5BLCzTGtLbBI+g
dilSJo1CnIm7GEXFxhT6PDDwfrs73/ywIQD/1ePD4r7Ou6ETsrq4mu7XcWfj++Pb58nJU/9i
PNtbjhan04/9GtX4qVYc814WDqt6FaX5s+ZwXXeq52lndT6IuVvlblytLMvh4Gzwaf90nsvz
2DF/21+20T/ldgp5s1jXRaN4t/8izsy/OUB6e/Qa79r+JwAAAAAAAL52vQVuGQAAAP6+my1w
ywAAAAAAAADwu14ATsEYtgBQAAA=
$ mount -t erofs -o cache_strategy=disabled foo.erofs /mnt
$ dd if=/mnt/data of=/dev/null bs=4096 count=1
CVE-2026-45884
Média · 5.5
CWE-191 27/05/2026
apparmor: avoid per-cpu hold underflow in aa_get_buffer
In the Linux kernel, the following vulnerability has been resolved:
apparmor: avoid per-cpu hold underflow in aa_get_buffer
When aa_get_buffer() pulls from the per-cpu list it unconditionally
decrements cache->hold. If hold reaches 0 while count is still non-zero,
the unsigned decrement wraps to UINT_MAX. This keeps hold non-zero for a
very long time, so aa_put_buffer() never returns buffers to the global
list, which can starve other CPUs and force repeated kmalloc(aa_g_path_max)
allocations.
Guard the decrement so hold never underflows.
CVE-2026-25104
Alta · 7.8
CWE-191 26/05/2026
Integer Underflow em Mediaarea Mediainfolib
A heap-based buffer overflow vulnerability exists in the LXF parsing functionality of MediaInfoLib (version(s): 26.01). A specially crafted .lxf file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.
CVE-2026-44069
Baixa · 3.9
CWE-191 21/05/2026
Integer underflow in volxlate
An integer underflow in the volxlate function in Netatalk 3.0.0 through 4.4.2 allows a local privileged user to obtain limited information, modify limited data, or cause a minor service disruption via crafted volume translation input.
CVE-2026-44060
Alta · 7.5
CWE-191 21/05/2026
Integer underflow in dsi_writeinit() leads to denial of service
An integer underflow in dsi_writeinit() in Netatalk 1.5.0 through 4.4.2 allows a remote unauthenticated attacker to cause a denial of service via a crafted DSI write request.
CVE-2026-42268
Alta · 7.5
CWE-191 12/05/2026
ModSecurity: Unsigned integer underflow in @verifySSN / @verifyCPF / @verifySVNR operators
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 to before 3.0.15, there is an unhandled exception (std::out_of_range) caused by unsigned integer underflow in libmodsecurity3 if the user (administrator) uses a rule any of @verifySSN, @verifyCPF, or @verifySVNR. This vulnerability is fixed in 3.0.15.
CVE-2026-34672
Média · 6.2
CWE-191 12/05/2026
CAI Content Credentials | Integer Underflow (Wrap or Wraparound) (CWE-191)
CAI Content Credentials versions c2pa-web@0.7.0, c2pa-v0.78.2 and earlier are affected by an Integer Underflow (Wrap or Wraparound) vulnerability that could result in an application denial-of-service. An attacker could exploit this vulnerability to crash the application, leading to a denial-of-service condition. Exploitation of this issue does not require user interaction.
CVE-2026-34667
Média · 6.2
CWE-191 12/05/2026
CAI Content Credentials | Integer Underflow (Wrap or Wraparound) (CWE-191)
CAI Content Credentials versions c2pa-web@0.7.0, c2pa-v0.78.2 and earlier are affected by an Integer Underflow (Wrap or Wraparound) vulnerability that could result in an application denial-of-service. An attacker could exploit this vulnerability to crash the application, leading to a denial-of-service condition. Exploitation of this issue does not require user interaction.
CVE-2026-40397
Alta · 7.8
CWE-191 12/05/2026
Windows Common Log File System Driver Elevation of Privilege Vulnerability
Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.
CVE-2026-43359
Média · 5.5
CWE-191 08/05/2026
btrfs: fix transaction abort on set received ioctl due to item overflow
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix transaction abort on set received ioctl due to item overflow
If the set received ioctl fails due to an item overflow when attempting to
add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction
since we did some metadata updates before.
This means that if a user calls this ioctl with the same received UUID
field for a lot of subvolumes, we will hit the overflow, trigger the
transaction abort and turn the filesystem into RO mode. A malicious user
could exploit this, and this ioctl does not even requires that a user
has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume.
Fix this by doing an early check for item overflow before starting a
transaction. This is also race safe because we are holding the subvol_sem
semaphore in exclusive (write) mode.
A test case for fstests will follow soon.
CVE-2026-43301
Média · 5.5
CWE-191 08/05/2026
media: chips-media: wave5: Fix PM runtime usage count underflow
In the Linux kernel, the following vulnerability has been resolved:
media: chips-media: wave5: Fix PM runtime usage count underflow
Replace pm_runtime_put_sync() with pm_runtime_dont_use_autosuspend() in
the remove path to properly pair with pm_runtime_use_autosuspend() from
probe. This allows pm_runtime_disable() to handle reference count cleanup
correctly regardless of current suspend state.
The driver calls pm_runtime_put_sync() unconditionally in remove, but the
device may already be suspended due to autosuspend configured in probe.
When autosuspend has already suspended the device, the usage count is 0,
and pm_runtime_put_sync() decrements it to -1.
This causes the following warning on module unload:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 963 at kernel/kthread.c:1430
kthread_destroy_worker+0x84/0x98
...
vdec 30210000.video-codec: Runtime PM usage count underflow!
CVE-2026-43187
Alta · 8.8
CWE-191 06/05/2026
xfs: delete attr leaf freemap entries when empty
In the Linux kernel, the following vulnerability has been resolved:
xfs: delete attr leaf freemap entries when empty
Back in commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size
underflow"), Brian Foster observed that it's possible for a small
freemap at the end of the end of the xattr entries array to experience
a size underflow when subtracting the space consumed by an expansion of
the entries array. There are only three freemap entries, which means
that it is not a complete index of all free space in the leaf block.
This code can leave behind a zero-length freemap entry with a nonzero
base. Subsequent setxattr operations can increase the base up to the
point that it overlaps with another freemap entry. This isn't in and of
itself a problem because the code in _leaf_add that finds free space
ignores any freemap entry with zero size.
However, there's another bug in the freemap update code in _leaf_add,
which is that it fails to update a freemap entry that begins midway
through the xattr entry that was just appended to the array. That can
result in the freemap containing two entries with the same base but
different sizes (0 for the "pushed-up" entry, nonzero for the entry
that's actually tracking free space). A subsequent _leaf_add can then
allocate xattr namevalue entries on top of the entries array, leading to
data loss. But fixing that is for later.
For now, eliminate the possibility of confusion by zeroing out the base
of any freemap entry that has zero size. Because the freemap is not
intended to be a complete index of free space, a subsequent failure to
find any free space for a new xattr will trigger block compaction, which
regenerates the freemap.
It looks like this bug has been in the codebase for quite a long time.
CVE-2026-43171
Média · 5.5
CWE-191 06/05/2026
EFI/CPER: don't dump the entire memory region
In the Linux kernel, the following vulnerability has been resolved:
EFI/CPER: don't dump the entire memory region
The current logic at cper_print_fw_err() doesn't check if the
error record length is big enough to handle offset. On a bad firmware,
if the ofset is above the actual record, length -= offset will
underflow, making it dump the entire memory.
The end result can be:
- the logic taking a lot of time dumping large regions of memory;
- data disclosure due to the memory dumps;
- an OOPS, if it tries to dump an unmapped memory region.
Fix it by checking if the section length is too small before doing
a hex dump.
[ rjw: Subject tweaks ]
CVE-2026-37534
Crítica · 9.8
CWE-191 01/05/2026
Integer underflow vulnerability in Open-SAE-J1939 thru commit…
Integer underflow vulnerability in Open-SAE-J1939 thru commit b6caf884df46435e539b1ecbf92b6c29b345bdfe (2025-11-30) in SAE_J1939_Read_Transport_Protocol_Data_Transfer,allows attackers to write to arbitrary memory via crafted sequence number from the CAN frame.
CVE-2026-33845
Crítica · 9.1
CWE-191 30/04/2026
Gnutls: gnutls: denial of service via dtls zero-length fragment
A flaw in GnuTLS DTLS handshake parsing allows malformed fragments with zero length and non-zero offset, leading to an integer underflow during reassembly and resulting in an out-of-bounds read. This issue is remotely exploitable and may cause information disclosure or denial of service.
CVE-2026-7424
Alta · 8.1
CWE-191 29/04/2026
Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
Integer underflow in the DHCPv6 sub-option parser in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network actor to corrupt the device's IPv6 address assignment, DNS configuration, and lease times, and to cause a denial of service (permanent IP task freeze requiring hardware reset) by sending a single crafted DHCPv6 packet.
The issue is present whenever DHCPv6 is enabled.
To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.
CVE-2026-7423
Média · 6.5
CWE-191 29/04/2026
Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP
Integer underflow in the ICMP and ICMPv6 echo reply handlers in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network user to cause a denial of service (device crash) when outgoing ping support is enabled, because header sizes are subtracted from a packet length field without validating the field is large enough, resulting in a heap out-of-bounds read of up to approximately 65KB.
To mitigate this issue, users should upgrade to the fixed version when available.
CVE-2026-6914
Alta · 7.5
CWE-191 29/04/2026
MD5 checksum creation may cause availability loss
Computing the MD5 checksum of a malformed BSON object under specific conditions may cause loss of availability in MongoDB server.
This issue affects all MongoDB Server v8.2 versions, all MongoDB Server v8.1 versions, MongoDB Server v8.0 versions prior to 8.0.21, MongoDB Server v7.0 versions prior to 7.0.32
CVE-2026-40356
Alta · 7.5
CWE-191 28/04/2026
Integer Underflow em Mit Kerberos 5
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.
CVE-2026-31662
Alta · 7.5
CWE-191 24/04/2026
tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG
The GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements
bc_ackers on every inbound group ACK, even when the same member has
already acknowledged the current broadcast round.
Because bc_ackers is a u16, a duplicate ACK received after the last
legitimate ACK wraps the counter to 65535. Once wrapped,
tipc_group_bc_cong() keeps reporting congestion and later group
broadcasts on the affected socket stay blocked until the group is
recreated.
Fix this by ignoring duplicate or stale ACKs before touching bc_acked or
bc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and
prevents the underflow path.
CVE-2026-31656
Alta · 7.8
CWE-191 24/04/2026
drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat
A use-after-free / refcount underflow is possible when the heartbeat
worker and intel_engine_park_heartbeat() race to release the same
engine->heartbeat.systole request.
The heartbeat worker reads engine->heartbeat.systole and calls
i915_request_put() on it when the request is complete, but clears
the pointer in a separate, non-atomic step. Concurrently, a request
retirement on another CPU can drop the engine wakeref to zero, triggering
__engine_park() -> intel_engine_park_heartbeat(). If the heartbeat
timer is pending at that point, cancel_delayed_work() returns true and
intel_engine_park_heartbeat() reads the stale non-NULL systole pointer
and calls i915_request_put() on it again, causing a refcount underflow:
```
<4> [487.221889] Workqueue: i915-unordered engine_retire [i915]
<4> [487.222640] RIP: 0010:refcount_warn_saturate+0x68/0xb0
...
<4> [487.222707] Call Trace:
<4> [487.222711] <TASK>
<4> [487.222716] intel_engine_park_heartbeat.part.0+0x6f/0x80 [i915]
<4> [487.223115] intel_engine_park_heartbeat+0x25/0x40 [i915]
<4> [487.223566] __engine_park+0xb9/0x650 [i915]
<4> [487.223973] ____intel_wakeref_put_last+0x2e/0xb0 [i915]
<4> [487.224408] __intel_wakeref_put_last+0x72/0x90 [i915]
<4> [487.224797] intel_context_exit_engine+0x7c/0x80 [i915]
<4> [487.225238] intel_context_exit+0xf1/0x1b0 [i915]
<4> [487.225695] i915_request_retire.part.0+0x1b9/0x530 [i915]
<4> [487.226178] i915_request_retire+0x1c/0x40 [i915]
<4> [487.226625] engine_retire+0x122/0x180 [i915]
<4> [487.227037] process_one_work+0x239/0x760
<4> [487.227060] worker_thread+0x200/0x3f0
<4> [487.227068] ? __pfx_worker_thread+0x10/0x10
<4> [487.227075] kthread+0x10d/0x150
<4> [487.227083] ? __pfx_kthread+0x10/0x10
<4> [487.227092] ret_from_fork+0x3d4/0x480
<4> [487.227099] ? __pfx_kthread+0x10/0x10
<4> [487.227107] ret_from_fork_asm+0x1a/0x30
<4> [487.227141] </TASK>
```
Fix this by replacing the non-atomic pointer read + separate clear with
xchg() in both racing paths. xchg() is a single indivisible hardware
instruction that atomically reads the old pointer and writes NULL. This
guarantees only one of the two concurrent callers obtains the non-NULL
pointer and performs the put, the other gets NULL and skips it.
(cherry picked from commit 13238dc0ee4f9ab8dafa2cca7295736191ae2f42)
CVE-2026-31617
Média · 5.5
CWE-191 24/04/2026
usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()
The block_len read from the host-supplied NTB header is checked against
ntb_max but has no lower bound. When block_len is smaller than
opts->ndp_size, the bounds check of:
ndp_index > (block_len - opts->ndp_size)
will underflow producing a huge unsigned value that ndp_index can never
exceed, defeating the check entirely.
The same underflow occurs in the datagram index checks against block_len
- opts->dpe_size. With those checks neutered, a malicious USB host can
choose ndp_index and datagram offsets that point past the actual
transfer, and the skb_put_data() copies adjacent kernel memory into the
network skb.
Fix this by rejecting block lengths that cannot hold at least the NTB
header plus one NDP. This will make block_len - opts->ndp_size and
block_len - opts->dpe_size both well-defined.
Commit 8d2b1a1ec9f5 ("CDC-NCM: avoid overflow in sanity checking") fixed
a related class of issues on the host side of NCM.
CVE-2026-31551
Média · 5.5
CWE-191 24/04/2026
wifi: mac80211: Fix static_branch_dec() underflow for aql_disable.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Fix static_branch_dec() underflow for aql_disable.
syzbot reported static_branch_dec() underflow in aql_enable_write(). [0]
The problem is that aql_enable_write() does not serialise concurrent
write()s to the debugfs.
aql_enable_write() checks static_key_false(&aql_disable.key) and
later calls static_branch_inc() or static_branch_dec(), but the
state may change between the two calls.
aql_disable does not need to track inc/dec.
Let's use static_branch_enable() and static_branch_disable().
[0]:
val == 0
WARNING: kernel/jump_label.c:311 at __static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311, CPU#0: syz.1.3155/20288
Modules linked in:
CPU: 0 UID: 0 PID: 20288 Comm: syz.1.3155 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311
Code: f2 c9 ff 5b 5d c3 cc cc cc cc e8 54 f2 c9 ff 48 89 df e8 ac f9 ff ff eb ad e8 45 f2 c9 ff 90 0f 0b 90 eb a2 e8 3a f2 c9 ff 90 <0f> 0b 90 eb 97 48 89 df e8 5c 4b 33 00 e9 36 ff ff ff 0f 1f 80 00
RSP: 0018:ffffc9000b9f7c10 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffff9b3e5d40 RCX: ffffffff823c57b4
RDX: ffff8880285a0000 RSI: ffffffff823c5846 RDI: ffff8880285a0000
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000a
R13: 1ffff9200173ef88 R14: 0000000000000001 R15: ffffc9000b9f7e98
FS: 00007f530dd726c0(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001140 CR3: 000000007cc4a000 CR4: 00000000003526f0
Call Trace:
<TASK>
__static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline]
__static_key_slow_dec kernel/jump_label.c:321 [inline]
static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336
aql_enable_write+0x2b2/0x310 net/mac80211/debugfs.c:343
short_proxy_write+0x133/0x1a0 fs/debugfs/file.c:383
vfs_write+0x2aa/0x1070 fs/read_write.c:684
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x1eb/0x250 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f530cf9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f530dd72028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f530d215fa0 RCX: 00007f530cf9aeb9
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00007f530d008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 4200000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f530d216038 R14: 00007f530d215fa0 R15: 00007ffde89fb978
</TASK>
CVE-2026-33999
Alta · 7.8
CWE-191 23/04/2026
Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling
A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.