# SUNRPC: harden gss_krb5_unwrap_v2 against short tokens

CVE record · `CVE-2026-89542`

- **Identifiers:** `CVE-2026-89542`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **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, 19:44 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.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before 299d281c7225ded15b28cb861a98d818d82787fc` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before 84ddbc8d084c0251d534f14f5d1a7da05be56404` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before 075d7cfc4df8c54cb202ba8b28420370c03ba9b6` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before f2591660e0eb263c9415bf0d0bb1b111e62df7a4` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before dddcb0f4b7e27fac16a78ea9a1c8ec2e8a241087` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before 806584a4b67a7233870c33e5b8f872e76dd02988` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before a7894e10572d53eb10109b8d07459cc8d3435811` (git)
  - affected: `de9c17eb4a912c9028f7b470eb80815144883b26 to before 6959297aaa9572783d620a226d73c3fb94494888` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.35`
  - unaffected: `before 2.6.35` (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

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0051, the 44th 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-2026-89542](https://www.cve.org/CVERecord?id=CVE-2026-89542)
- [NVD: CVE-2026-89542](https://nvd.nist.gov/vuln/detail/CVE-2026-89542)

### References from the CNA

- <https://git.kernel.org/stable/c/299d281c7225ded15b28cb861a98d818d82787fc>
- <https://git.kernel.org/stable/c/84ddbc8d084c0251d534f14f5d1a7da05be56404>
- <https://git.kernel.org/stable/c/075d7cfc4df8c54cb202ba8b28420370c03ba9b6>
- <https://git.kernel.org/stable/c/f2591660e0eb263c9415bf0d0bb1b111e62df7a4>
- <https://git.kernel.org/stable/c/dddcb0f4b7e27fac16a78ea9a1c8ec2e8a241087>
- <https://git.kernel.org/stable/c/806584a4b67a7233870c33e5b8f872e76dd02988>
- <https://git.kernel.org/stable/c/a7894e10572d53eb10109b8d07459cc8d3435811>
- <https://git.kernel.org/stable/c/6959297aaa9572783d620a226d73c3fb94494888>

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-2026-89542>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89542/>. Everything for agents: <https://agentprime.io/llms.txt>.