CVE-2026-43456 — bonding: fix type confusion in bond_setup_by_slave()
In the Linux kernel, the following vulnerability has been resolved: bonding: fix type confusion in bond_setup_by_slave() kernel BUG at net/core/skbuff.c:2306! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:pskb_expand_head+0xa08/0xfe0 net/core/skbuff.c:2306 RSP: 0018:ffffc90004aff760 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88807e3c8780 RCX: ffffffff89593e0e RDX: ffff88807b7c4900 RSI: ffffffff89594747 RDI: ffff88807b7c4900 RBP: 0000000000000820 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000961a63e0 R11: 0000000000000000 R12: ffff88807e3c8780 R13: 00000000961a6560 R14: dffffc0000000000 R15: 00000000961a63e0 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1a0ed8df0 CR3: 000000002d816000 CR4: 00000000003526f0 Call Trace: <TASK> ipgre_header+0xdd/0x540 net/ipv4/ip_gre.c:900 dev_hard_header include/linux/netdevice.h:3439 [inline] packet_snd net/packet/af_packet.c:3028 [inline] packet_sendmsg+0x3ae5/0x53c0 net/packet/af_packet.c:3108 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe1a0e6c1a9 When a non-Ethernet device (e.g. GRE tunnel) is enslaved to a bond, bond_setup_by_slave() directly copies the slave's header_ops to the bond device: bond_dev->header_ops = slave_dev->header_ops; This causes a type confusion when dev_hard_header() is later called on the bond device. Functions like ipgre_header(), ip6gre_header(),all use netdev_priv(dev) to access their device-specific private data. When called with the bond device, netdev_priv() returns the bond's private data (struct bonding) instead of the expected type (e.g. struct ip_tunnel), leading to garbage values being read and kernel crashes. Fix this by introducing bond_header_ops with wrapper functions that delegate to the active slave's header_ops using the slave's own device. This ensures netdev_priv() in the slave's header functions always receives the correct device. The fix is placed in the bonding driver rather than individual device drivers, as the root cause is bond blindly inheriting header_ops from the slave without considering that these callbacks expect a specific netdev_priv() layout. The type confusion can be observed by adding a printk in ipgre_header() and running the following commands: ip link add dummy0 type dummy ip addr add 10.0.0.1/24 dev dummy0 ip link set dummy0 up ip link add gre1 type gre local 10.0.0.1 ip link add bond1 type bond mode active-backup ip link set gre1 master bond1 ip link set gre1 up ip link set bond1 up ip addr add fe80::1/64 dev bond1
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)+1
- 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)
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 (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 |
|---|---|---|---|---|
| Linux | Linux | ≥ 1284cd3a2b740d0118458d2ea470a1e5bc19b187 and < 5d0fb9806ab6cf2c3cfba0e1b8c701da65e25af8≥ 1284cd3a2b740d0118458d2ea470a1e5bc19b187 and < 9baf26a91565b7bb2b1d9f99aaf884a2b28c2f6d≥ 1284cd3a2b740d0118458d2ea470a1e5bc19b187 and < 6ac890f1d60ac3707ee8dae15a67d9a833e49956≥ 1284cd3a2b740d0118458d2ea470a1e5bc19b187 and < 95597d11dc8bddb2b9a051c9232000bfbb5e43ba≥ 1284cd3a2b740d0118458d2ea470a1e5bc19b187 and < 950803f7254721c1c15858fbbfae3deaaeeecb11version 2.6.24 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 2.6.24 and < 6.12.78≥ 6.13 and < 6.18.19≥ 6.19 and < 6.19.9version 7.0-rc1version 7.0-rc2version 7.0-rc3 | 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 |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.16%
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
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
5 on the record
- git.kernel.org/stable/c/9baf26a91565b7bb2b1d9f99aaf884a2b28c2f6d
- git.kernel.org/stable/c/6ac890f1d60ac3707ee8dae15a67d9a833e49956
- git.kernel.org/stable/c/950803f7254721c1c15858fbbfae3deaaeeecb11
- git.kernel.org/stable/c/95597d11dc8bddb2b9a051c9232000bfbb5e43ba
- git.kernel.org/stable/c/5d0fb9806ab6cf2c3cfba0e1b8c701da65e25af8
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 15h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 15h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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-2026-43456 is "bonding: fix type confusion in bond_setup_by_slave()", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.16% 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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