CVE-2026-43374net: nexthop: fix percpu use-after-free in remove_nh_grp_entry
- 7.8HighCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 95% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix percpu use-after-free in remove_nh_grp_entry When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed.
Timeline
ID reserved
By Linux
- 7 days later
· 7 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected f4676ea74b8549cd88dbfe2a592ce4530039e61f – < abf4feaee6405f1441929c6ebe7a250f2cd170a7
- affected f4676ea74b8549cd88dbfe2a592ce4530039e61f – < ab5ebab9664214ba41a7633cb4e72f128204f924
- affected f4676ea74b8549cd88dbfe2a592ce4530039e61f – < 9e08ad731862b22a87cc55f752e16d66cdc9e231
- affected f4676ea74b8549cd88dbfe2a592ce4530039e61f – < b2662e7593e94ae09b1cf7ee5f09160a3612bcb2
- affected 6.9
- unaffected < 6.9
- unaffected 6.12.78 – ≤ 6.12.*
- unaffected 6.18.19 – ≤ 6.18.*
- unaffected 6.19.9 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References4
- https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7 (opens in a new tab)
- https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924 (opens in a new tab)
- https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231 (opens in a new tab)
- https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-28680 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-43374)Record last updated .