CVE-2026-43374: Linux kernel · net: nexthop: fix percpu use-after-free in remove_nh_grp_entry
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in b2662e7593e94ae09b1cf7ee5f09160a3612bcb2, abf4feaee6405f1441929c6ebe7a250f2cd170a7, ab5ebab9664214ba41a7633cb4e72f128204f924 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to b2662e7593e94ae09b1cf7ee5f09160a3612bcb2, abf4feaee6405f1441929c6ebe7a250f2cd170a7, ab5ebab9664214ba41a7633cb4e72f128204f924 or 9e08ad731862b22a87cc55f752e16d66cdc9e231.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in the Linux kernel. The fix defers freeing percpu stats until after the RCU grace period completes, preventing use-after-free. Users should update to a Linux kernel version that includes the fix identified by commits b2662b7593e94ae09b1cf7ee5f09160a3612bcb2, abf4feaee6405f1441929c6ebe7a250f2cd170a7, ab5ebab9664214ba41a7633cb4e72f128204f924, or 9e08ad731862b22a87cc55f752e16d66cdc9e231. No other mitigation is indicated by the vendor advisory.
Description
CVE-2026-43374 is a use-after-free vulnerability in the Linux kernel's nexthop component. It occurs when removing a nexthop from a group, where percpu stats are freed prematurely before the RCU grace period completes. This can lead to dereferencing freed memory, causing potential system instability or compromise. The issue has been fixed by deferring the freeing of percpu stats until after the RCU grace period. The vulnerability has a high severity with a CVSS score of 7.8.
References
- git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7 (opens in a new tab)
- git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924 (opens in a new tab)
- git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231 (opens in a new tab)
- git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 (opens in a new tab)