# SUNRPC: Reject krb5 v2 wrap tokens with oversized ec field

CVE record · `CVE-2026-89538`

- **Identifiers:** `CVE-2026-89538`
- **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: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before ac9efc29346b6942e71f0e24a3178a9121330fab` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before b5746095b59f4d11f39f08751d36bbdfd1e5deac` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before 9fc6d6e6db49ab55208d5dd1c424c1d0d9aa7296` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before 4abb44a29bb515df6f49123848765c70fc9b5021` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before dfcd81ab45613d45996fbf483d4ef54b0ec90ab9` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before 1f9856af065b6158271687e9788407b9573fd16f` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before 880effc943ed82d6811f272ed3307c222b40f4d6` (git)
  - affected: `cf4c024b908353fcc48309374d39e3399d67dfd1 to before ad484748eec0a66eac0f13ab53b3fbedb7333c91` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `3.13`
  - unaffected: `before 3.13` (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:** 0.0071, the 54th 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-2026-89538](https://www.cve.org/CVERecord?id=CVE-2026-89538)
- [NVD: CVE-2026-89538](https://nvd.nist.gov/vuln/detail/CVE-2026-89538)

### References from the CNA

- <https://git.kernel.org/stable/c/ac9efc29346b6942e71f0e24a3178a9121330fab>
- <https://git.kernel.org/stable/c/b5746095b59f4d11f39f08751d36bbdfd1e5deac>
- <https://git.kernel.org/stable/c/9fc6d6e6db49ab55208d5dd1c424c1d0d9aa7296>
- <https://git.kernel.org/stable/c/4abb44a29bb515df6f49123848765c70fc9b5021>
- <https://git.kernel.org/stable/c/dfcd81ab45613d45996fbf483d4ef54b0ec90ab9>
- <https://git.kernel.org/stable/c/1f9856af065b6158271687e9788407b9573fd16f>
- <https://git.kernel.org/stable/c/880effc943ed82d6811f272ed3307c222b40f4d6>
- <https://git.kernel.org/stable/c/ad484748eec0a66eac0f13ab53b3fbedb7333c91>

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-2026-89538>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89538/>. Everything for agents: <https://agentprime.io/llms.txt>.