CVE-2026-80836 crypto: virtio - bound the akcipher result length
A malicious virtio backend can trigger an out-of-bounds read in the Linux kernel crypto subsystem, leaking adjacent kernel heap memory to the caller.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80836?
CVE-2026-80836 is a vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
crypto: virtio - bound the akcipher result length
virtio_crypto_dataq_akcipher_callback() sets the result length from the device-reported response length without bounding it to the destination buffer, which was allocated for the original request length. sg_copy_from_buffer() then reads that many bytes from the destination buffer; a backend reporting a larger length over-reads adjacent kernel heap into the caller's scatterlist (an out-of-bounds read).
Clamp the reported length to the originally requested destination length. A conforming device reports no more than that, so valid results are unaffected.
Which versions are affected by CVE-2026-80836?
How do I fix CVE-2026-80836?
Apply the vendor's patch.
Is CVE-2026-80836 being exploited?
There is no known exploitation of CVE-2026-80836 in the wild and no public exploit code.
Sources
Also known as AZL-99546, BELL-CVE-2026-80836, DEBIAN-CVE-2026-80836, GHSA-4c27-p37x-4j2h, UBUNTU-CVE-2026-80836.