CVE-2026-97522 mptcp: fix bad accounting in __mptcp_subflow_push_pending()
A bug in Linux kernel MPTCP accounting can cause byte counter mismatches, potentially leading to denial of service conditions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97522?
CVE-2026-97522 is a denial of service vulnerability in Linux, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix bad accounting in __mptcp_subflow_push_pending()
If __subflow_push_pending() errors out we should avoid updating the copied byte counters, to avoid mismatch push call later on.
Which versions are affected by CVE-2026-97522?
How do I fix CVE-2026-97522?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-97522 being exploited?
There is no known exploitation of CVE-2026-97522 in the wild and no public exploit code.
Sources
Also known as AZL-104567, BELL-CVE-2026-97522, DEBIAN-CVE-2026-97522, GHSA-pwwm-ccjp-fwfv, UBUNTU-CVE-2026-97522.