CVE-2026-68125 mac802154: llsec: reject frames shorter than the authentication tag
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-68125?
CVE-2026-68125 is a high-severity vulnerability in Linux, published on 10 Aug 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
mac802154: llsec: reject frames shorter than the authentication tag
llsec_do_decrypt_auth() computes the associated-data length for the AEAD request as
assoclen += datalen - authlen;
where datalen is the number of bytes after the MAC header and authlen (4, 8 or 16) is the length of the authentication tag. Nothing verifies that the frame actually carries at least authlen payload bytes. A secured frame whose payload is shorter than the tag makes datalen - authlen negative; assoclen is then passed to aead_request_set_ad() as an unsigned value close to 4 GiB, so crypto_aead_decrypt() walks far off the end of the scatterlist that only spans the real frame.
The frame is fully attacker-controlled and reaches this path from any IEEE 802.15.4 peer in radio range. Reject frames whose payload is shorter than the authentication tag before the subtraction.
Dynamically reproduced on a KASAN kernel as a general-protection-fault in the AEAD scatterwalk, and the fix confirmed.
Weakness: CWE-190
Which versions are affected by CVE-2026-68125?
How do I fix CVE-2026-68125?
Upgrade to a fixed version.
Is CVE-2026-68125 being exploited?
There is no known exploitation of CVE-2026-68125 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68125, DEBIAN-CVE-2026-68125, GHSA-pj3j-hrq9-5j4f, UBUNTU-CVE-2026-68125.