# lib/ucs2_string.c: fix out-of-bounds read in ucs2_strnlen()

CVE record · `CVE-2026-89726`

- **Identifiers:** `CVE-2026-89726`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:46 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 04ae68af4107600120c3c41c94268f43bc350d48` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2e5a70a175f0c74e7238b013a96c4eabc3002934` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 3ada20e110bf3245edb0a3bcddadc33d0f142f8d` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 60c74f42f5abddb85dd919b4448d5474e65dbe76` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 709eb41adaf78d59d4579a13a898125919b69bcc` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7d658da725ea81c91f73087547b97e7ced82d62b` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 1b0dc3cbb8630f0b5cb34d848628225920a904be` (git)
  - affected: `1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before cec0d03fe785380540dc1b4d07c80f67ae2ffc78` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.12`
  - unaffected: `before 2.6.12` (semver)
  - unaffected: `5.10.270 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.221 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.188 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.157 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0018, the 7th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89726](https://www.cve.org/CVERecord?id=CVE-2026-89726)
- [NVD: CVE-2026-89726](https://nvd.nist.gov/vuln/detail/CVE-2026-89726)

### References from the CNA

- <https://git.kernel.org/stable/c/04ae68af4107600120c3c41c94268f43bc350d48>
- <https://git.kernel.org/stable/c/2e5a70a175f0c74e7238b013a96c4eabc3002934>
- <https://git.kernel.org/stable/c/3ada20e110bf3245edb0a3bcddadc33d0f142f8d>
- <https://git.kernel.org/stable/c/60c74f42f5abddb85dd919b4448d5474e65dbe76>
- <https://git.kernel.org/stable/c/709eb41adaf78d59d4579a13a898125919b69bcc>
- <https://git.kernel.org/stable/c/7d658da725ea81c91f73087547b97e7ced82d62b>
- <https://git.kernel.org/stable/c/1b0dc3cbb8630f0b5cb34d848628225920a904be>
- <https://git.kernel.org/stable/c/cec0d03fe785380540dc1b4d07c80f67ae2ffc78>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89726>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89726/>. Everything for agents: <https://agentprime.io/llms.txt>.