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.
CSIRTS triage
- What
- Network scheduler CAKE qdisc triggers kernel warning and potential crash on malformed ACK packets.
- Who is affected
- Linux systems using CAKE qdisc for traffic shaping.
- Urgency
- High priority; denial of service via crafted packets with CVSS 7.5.
- Action
- Apply kernel patch to remove WARN_ON(1) and properly handle malformed packets.
AI-assisted analysis generated from the source advisory — verify against the original.
⚡ Watch CVE-2026-74704
Get an email if CVE-2026-74704 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.
Exploitation outlook
- Low exploitation risk0.18% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 7% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
Embed the live status
— this badge updates automatically when the KEV or exploit status changes. How to embed it →
[](https://www.csirts.com/cve/CVE-2026-74704)