CVE-2026-97609netfilter: cttimeout: prevent UAF during module unload
- 7.0HighCVSS base score
- 0.14%Exploitation in 30 daysEPSS · top 96% 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: netfilter: cttimeout: prevent UAF during module unload nf_ct_set_timeout() protects the timeout hook dereference and policy lookup with rcu_read_lock(). cttimeout_exit(), however, unregisters the per-net operations before it clears the hook. This allows the following interleaving: CPU 0 CPU 1 cttimeout_exit() nf_ct_set_timeout() unregister_pernet_subsys() rcu_read_lock() kfree(pernet) h = nf_ct_timeout_hook h->timeout_find_get() nfct_timeout_pernet() The hook still points to ctnl_timeout_find_get() when CPU 1 looks up the already freed per-net timeout list. KASAN reported: BUG: KASAN: slab-use-after-free in ctnl_timeout_find_get Read of size 8 by task poc/90 Call Trace: ctnl_timeout_find_get+0x271/0x2a0 [nfnetlink_cttimeout] nf_ct_set_timeout+0x7b/0x3c0 xt_ct_tg_check+0x724/0xb20 xt_check_target+0x234/0xa90 do_ipt_set_ctl+0x570/0x1270 Allocated by task 89: __kmalloc_noprof+0x16e/0x460 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 Freed by task 91: kfree+0x131/0x390 ops_undo_list+0x3d4/0x730 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 cttimeout_exit+0x52/0x970 [nfnetlink_cttimeout] Clear the hook and wait for existing readers before unregistering the per-net operations. This blocks new policy lookups and ensures readers that observed the hook finish before the per-net storage is freed.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 35 days later
· 35 days 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 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.14% · top 96% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Affected products
- affected ebfbe67568a734a449203097b02c4ab884257535 – < 763787e9d43982d1082b59caeabd317343b153ea
- affected ebfbe67568a734a449203097b02c4ab884257535 – < f664e06699829a31e95675a6864655a6c5f9904f
- affected ebfbe67568a734a449203097b02c4ab884257535 – < 73f353bec62509c776184e49a031c6145cec0d05
- affected ebfbe67568a734a449203097b02c4ab884257535 – < a7fdd86c386b7f7cc72a126389c2cdb55d035221
- affected ebfbe67568a734a449203097b02c4ab884257535 – < 1f69c570a73f2dedf75ea5166d47622d5fa958c1
- affected ebfbe67568a734a449203097b02c4ab884257535 – < fec9b1de0d02de8dafa3cc344bcb91cf28660643
- affected 5.13
- unaffected < 5.13
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.112 – ≤ 6.12.*
- unaffected 6.18.53 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References6
- https://git.kernel.org/stable/c/763787e9d43982d1082b59caeabd317343b153ea (opens in a new tab)
- https://git.kernel.org/stable/c/f664e06699829a31e95675a6864655a6c5f9904f (opens in a new tab)
- https://git.kernel.org/stable/c/73f353bec62509c776184e49a031c6145cec0d05 (opens in a new tab)
- https://git.kernel.org/stable/c/a7fdd86c386b7f7cc72a126389c2cdb55d035221 (opens in a new tab)
- https://git.kernel.org/stable/c/1f69c570a73f2dedf75ea5166d47622d5fa958c1 (opens in a new tab)
- https://git.kernel.org/stable/c/fec9b1de0d02de8dafa3cc344bcb91cf28660643 (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-2026-86740 (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-2026-97609)Record last updated .