CVE-2026-74704
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_cake: drop WARN_ON(1) for malformed packets in ACK filter The sch_cake ACK filter parses packets to find the TCP header and filter duplicated ACKs if the flow is backlogged. The parsing code contains a WARN_ON(1) which can be triggered by a malformed IP header in certain cases. Depending on the system configuration, this leads either to either spamming dmesg with warnings, or a panic if panic_on_warn is set. The code already correctly skips the offending packet in the branch that triggers the warning, so the WARN_ON itself doesn't really serve any purpose. So just drop it altogether to avoid the inconvenient side effects.
Affected versions
Linux kernel versions
4.19
and later are affected. Fixed in
5.10.265,
5.15.216,
6.1.183,
6.6.152,
6.12.104,
6.18.45,
7.1.9,
7.2
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-74704?
CVE-2026-74704 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.19 onward and has been patched in 5.10.265, 5.15.216, 6.1.183 and others. CVE-2026-74704 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-74704?
Yes. CVE-2026-74704 has been patched. Fixed versions include 5.10.265, 5.15.216, 6.1.183 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-74704 actively exploited?
No. CVE-2026-74704 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.