What’s Vulnerable › Vulnerabilities

CVE-2022-49561: netfilter: conntrack: re-fetch conntrack after insertion

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-26 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: re-fetch conntrack after insertion In case the conntrack is clashing, insertion can free skb->_nfct and set skb->_nfct to the already-confirmed entry. This wasn't found before because the conntrack entry and the extension space used to free'd after an rcu grace period, plus the race needs events enabled to trigger.

Affected products

• Linux kernel: from 4.7 before 4.14.282; from 4.15 before 4.19.246; from 4.20 before 5.4.197; from 5.5 before 5.10.120; from 5.11 before 5.15.45; from 5.16 before 5.17.13 — fixed in 4.14.282, 4.19.246, 5.10.120, 5.15.45, 5.17.13, 5.18.2

How to fix

Upgrade to a fixed version: Linux kernel 4.14.282, 4.19.246, 5.10.120, 5.15.45. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/01989d7eebb61c99bd4b88ebc8e261bd2f02caed
• https://git.kernel.org/stable/c/04e4a11dc723c52db7a36dc58f0d69ce6426f8f0
• https://git.kernel.org/stable/c/04f9e9104c969d8ce10a4a43634f641ed082092d
• https://git.kernel.org/stable/c/56b14ecec97f39118bf85c9ac2438c5a949509ed
• https://git.kernel.org/stable/c/91a36ec160ec1a0c8f5352b772dffcbb0b6023e3
• https://git.kernel.org/stable/c/92a999d1963eed0df666284e20055136ceabd12f
• https://git.kernel.org/stable/c/b16bb373988da3ceb0308381634117e18b6ec60d
• https://git.kernel.org/stable/c/e97222b785e70e8973281666d709baad6523d8af

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