CVE-2026-74347netfilter: cttimeout: detach dataplane timeout policy and repurpose refcount
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% 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: detach dataplane timeout policy and repurpose refcount Add a refcount for struct nf_ct_timeout which is used by ct extension to set the custom ct timeout policy, this tells us that the ct timeout is being used by a conntrack entry. When the last conntrack entry drops the refcount on the ct timeout, the ct timeout is released. Remove the refcount for control plane which controls if the ruleset refers to the timeout policy. After this update, it is possible to remove the ct timeout policy from nfnetlink_cttimeout immediately. This is for simplicity not to handle two refcounts on a single object. Remove nf_queue_nf_hook_drop(): a packet sitting in nfqueue will just hold a reference to the nf_ct_timeout object until packet is reinjected, since this is part of the ct extension, this will be released by the time the conntrack is freed. nf_ct_untimeout() is still called to clean up in a best effort basis: the ct timeout on existing entries gets removed when the ct timeout goes away, but as long as the iptables ruleset still refers to the ct timeout through a template, new conntracks may keep attaching it and extend its lifetime until the rule is removed. nf_ct_untimeout() is not called anymore from module removal path, this is unlikely to find timeouts give module refcount is bumped, and the new refcount already tracks the ct timeout policy use so it is released when unused.
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 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 · Received | 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)
- 0.13% · top 97% 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 50978462300f74dc48aea4a38471cb69bdf741a5 – < b512f4bacb73219bd525b5189a26143cabd7b38c
- affected 50978462300f74dc48aea4a38471cb69bdf741a5 – < 1241e459a1bd17044fa6bbb68f491ab5543c3a1b
- affected 50978462300f74dc48aea4a38471cb69bdf741a5 – < b2e84317f334d834fb06c9b340ea465f398b6d4f
- affected 50978462300f74dc48aea4a38471cb69bdf741a5 – < 44583fd5735cb0bdf3bfe11b1e51504ce387bdb7
- affected 50978462300f74dc48aea4a38471cb69bdf741a5 – < 9aeb0dcfeb460d33d61d434148b51103ab1d2013
- affected 50978462300f74dc48aea4a38471cb69bdf741a5 – < 7d6a9cdb8d3a51d9cfe546a09a518ab3d2671549
- affected 3.4
- unaffected < 3.4
- 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 7.1.5 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References6
- https://git.kernel.org/stable/c/b512f4bacb73219bd525b5189a26143cabd7b38c (opens in a new tab)
- https://git.kernel.org/stable/c/1241e459a1bd17044fa6bbb68f491ab5543c3a1b (opens in a new tab)
- https://git.kernel.org/stable/c/b2e84317f334d834fb06c9b340ea465f398b6d4f (opens in a new tab)
- https://git.kernel.org/stable/c/44583fd5735cb0bdf3bfe11b1e51504ce387bdb7 (opens in a new tab)
- https://git.kernel.org/stable/c/9aeb0dcfeb460d33d61d434148b51103ab1d2013 (opens in a new tab)
- https://git.kernel.org/stable/c/7d6a9cdb8d3a51d9cfe546a09a518ab3d2671549 (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-2026-59494 (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-2026-74347)Record last updated .