# CVE-2026-68125: mac802154: llsec: reject frames shorter than the authentication tag


- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-68125, DEBIAN-CVE-2026-68125, GHSA-pj3j-hrq9-5j4f, UBUNTU-CVE-2026-68125

## 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 (Integer Overflow or Wraparound)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68125 and fix it if it is affected.

What it is: CVE-2026-68125 is a high-severity vulnerability in Linux, published on 10 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-68125 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-68125/ (Markdown: https://insights.sbomify.com/CVE-2026-68125/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68125
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68125
- OSV: https://osv.dev/vulnerability/CVE-2026-68125

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68125/
Summaries are generated and may contain mistakes; the official description above is the record.