CVE-2025-37780 — isofs: Prevent the use of too small fid
In the Linux kernel, the following vulnerability has been resolved: isofs: Prevent the use of too small fid syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1] The handle_bytes value passed in by the reproducing program is equal to 12. In handle_to_path(), only 12 bytes of memory are allocated for the structure file_handle->f_handle member, which causes an out-of-bounds access when accessing the member parent_block of the structure isofs_fid in isofs, because accessing parent_block requires at least 16 bytes of f_handle. Here, fh_len is used to indirectly confirm that the value of handle_bytes is greater than 3 before accessing parent_block. [1] BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466 CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x198/0x550 mm/kasan/report.c:521 kasan_report+0xd8/0x138 mm/kasan/report.c:634 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183 exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523 do_handle_to_path+0xa0/0x198 fs/fhandle.c:257 handle_to_path fs/fhandle.c:385 [inline] do_handle_open+0x8cc/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 6466: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x32c/0x54c mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] handle_to_path fs/fhandle.c:357 [inline] do_handle_open+0x5a4/0xb8c fs/fhandle.c:403 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline] __se_sys_open_by_handle_at fs/fhandle.c:434 [inline] __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 11.0 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux |
version 2.6.12≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 0405d4b63d082861f4eaff9d39c78ee9dc34f845≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 007124c896e7d4614ac1f6bd4dedb975c35a2a8e≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 56dfffea9fd3be0b3795a9ca6401e133a8427e0b≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 952e7a7e317f126d0a2b879fc531b716932d5ffa≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 0fdafdaef796816a9ed0fd7ac812932d569d9beb≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 63d5a3e207bf315a32c7d16de6c89753a759f95a≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < 5e7de55602c61c8ff28db075cc49c8dd6989d7e0 and 1 more≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and < ee01a309ebf598be1ff8174901ed6e91619f1749 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 2.6.12-rc5version 6.15-rc2version 6.15-rc1version 2.6.12-rc4version 2.6.12-rc3version 2.6.12-rc2version 2.6.12≥ 6.13 and < 6.14.4 and 6 more≥ 6.7 and < 6.12.25≥ 6.2 and < 6.6.88≥ 5.16 and < 6.1.135≥ 5.11 and < 5.15.181≥ 5.5 and < 5.10.237≥ 2.6.13 and < 5.4.293 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.1 | CVSS 3.1 | High | 1.8 | 5.2 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.1 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- Affected products added · linux/linux kernel, debian/debian linux
- CVSS changed · 7.1
- Source status changed · → Analyzed
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
12 on the record
- git.kernel.org/stable/c/56dfffea9fd3be0b3795a9ca6401e133a8427e0b
- git.kernel.org/stable/c/63d5a3e207bf315a32c7d16de6c89753a759f95a
- git.kernel.org/stable/c/952e7a7e317f126d0a2b879fc531b716932d5ffa
- git.kernel.org/stable/c/007124c896e7d4614ac1f6bd4dedb975c35a2a8e
- git.kernel.org/stable/c/0fdafdaef796816a9ed0fd7ac812932d569d9beb
- git.kernel.org/stable/c/5e7de55602c61c8ff28db075cc49c8dd6989d7e0
- git.kernel.org/stable/c/ee01a309ebf598be1ff8174901ed6e91619f1749
- git.kernel.org/stable/c/0405d4b63d082861f4eaff9d39c78ee9dc34f845
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- nvd.nist.gov/vuln/detail/CVE-2025-37780
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- github.com/advisories/GHSA-w595-4hr6-r5fv
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-37780 is "isofs: Prevent the use of too small fid", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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