# fou: reject omitted FOU_ATTR_IPPROTO on FOU_ENCAP_DIRECT

CVE record · `CVE-2026-98541`

- **Identifiers:** `CVE-2026-98541`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 18 Oct 2026, 15:18 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: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before fd20220f86947d66d4dba2d76f13a28dbd86ef30` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before 46b1ffb7e169c7e401dd890b29e55dbc261f8f01` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before 7f4ba56f5d310dd018972916167985010a5d66a1` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before 3bcc1624cc1cdcc05b566475d6e848093ab2a8f6` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before 8b43f40798bb2758489fbbcae7e841ad4443c213` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before b1229b210ef5a39c58be665e6798203751411842` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before 520cf06b8ea0ba5bcc1b8b982ef07f02b5e56221` (git)
  - affected: `23461551c00628c3f3fe9cf837bf53cf8f212b63 to before d22609f3d13fc5baacd92c222731b03c593401db` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `3.18`
  - unaffected: `before 3.18` (semver)
  - unaffected: `5.10.271 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.222 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.189 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.158 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.112 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.55 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.9 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:** 0.0022, the 12th percentile, on 8 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 18 Oct 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-98541](https://www.cve.org/CVERecord?id=CVE-2026-98541)
- [NVD: CVE-2026-98541](https://nvd.nist.gov/vuln/detail/CVE-2026-98541)

### References from the CNA

- <https://git.kernel.org/stable/c/fd20220f86947d66d4dba2d76f13a28dbd86ef30>
- <https://git.kernel.org/stable/c/46b1ffb7e169c7e401dd890b29e55dbc261f8f01>
- <https://git.kernel.org/stable/c/7f4ba56f5d310dd018972916167985010a5d66a1>
- <https://git.kernel.org/stable/c/3bcc1624cc1cdcc05b566475d6e848093ab2a8f6>
- <https://git.kernel.org/stable/c/8b43f40798bb2758489fbbcae7e841ad4443c213>
- <https://git.kernel.org/stable/c/b1229b210ef5a39c58be665e6798203751411842>
- <https://git.kernel.org/stable/c/520cf06b8ea0ba5bcc1b8b982ef07f02b5e56221>
- <https://git.kernel.org/stable/c/d22609f3d13fc5baacd92c222731b03c593401db>

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-2026-98541>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-98541/>. Everything for agents: <https://agentprime.io/llms.txt>.