Linux Kernel: ref leak via nf_conntrack_expect expectation path
CVE-2026-31414 Published on April 13, 2026
netfilter: nf_conntrack_expect: use expect->helper
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_expect: use expect->helper
Use expect->helper in ctnetlink and /proc to dump the helper name.
Using nfct_help() without holding a reference to the master conntrack
is unsafe.
Use exp->master->helper in ctnetlink path if userspace does not provide
an explicit helper when creating an expectation to retain the existing
behaviour. The ctnetlink expectation path holds the reference on the
master conntrack and nf_conntrack_expect lock and the nfnetlink glue
path refers to the master ct that is attached to the skb.
Products Associated with CVE-2026-31414
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781 is affected.
- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below e7ccaa0a62a8ff2be5d521299ce79390c318d306 is affected.
- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below 4bd1b3d839172724b33d8d02c5a4ff6a1c775417 is affected.
- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below b53294bff19e56ada2f230ceb8b1ffde61cc3817 is affected.
- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below 3dfd3f7712b5a800f2ba632179e9b738076a51f0 is affected.
- Version ea781f197d6a835cbb93a0bf88ee1696296ed8aa and below f01794106042ee27e54af6fdf5b319a2fe3df94d is affected.
- Version 2.6.30 is affected.
- Before 2.6.30 is unaffected.
- Version 6.1.168, <= 6.1.* is unaffected.
- Version 6.6.134, <= 6.6.* is unaffected.
- Version 6.12.81, <= 6.12.* is unaffected.
- Version 6.18.22, <= 6.18.* is unaffected.
- Version 6.19.12, <= 6.19.* is unaffected.
- Version 7.0, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.