CVE-2026-74425 afs: handle CB.InitCallBackState3 requests without a server record
A missing check in the Linux kernel AFS callback handler can cause a null pointer dereference, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74425?
CVE-2026-74425 is a high-severity vulnerability in Linux, published on 15 Aug 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:
afs: handle CB.InitCallBackState3 requests without a server record
The cache manager callback path now attaches the server record to an incoming call through the rxrpc peer's app data. That association is not guaranteed to exist for every callback request, and most callback handlers already tolerate that case.
Make CB.InitCallBackState3 follow the same pattern by checking whether a server record was attached before using it. If the peer is not mapped to a server record, trace the request and ignore it, matching the existing behaviour for other unmatched callback requests.
This keeps the callback handler consistent with the rest of the cache manager service and avoids depending on peer state that may not be available for a given request.
Which versions are affected by CVE-2026-74425?
How do I fix CVE-2026-74425?
Apply the vendor's patch.
Is CVE-2026-74425 being exploited?
There is no known exploitation of CVE-2026-74425 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74425, DEBIAN-CVE-2026-74425, GHSA-pvfc-84wr-qwjc, UBUNTU-CVE-2026-74425.