CVE-2026-74347

CVE CVE-2026-74347EUVD EUVD-2026-59494Published 2026-08-15T05:58:35.000ZLast changed 2026-08-17T05:46:11.000ZCVSS 7.8

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 0; 50978462300f74dc48aea4a38471cb69bdf741a5 <7d6a9cdb8d3a51d9cfe546a09a518ab3d2671549; patch: 7.1.5; 50978462300f74dc48aea4a38471cb69bdf741a5 <9aeb0dcfeb460d33d61d434148b51103ab1d2013; 3.4; patch: 7.2

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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