# seg6: reset IP6CB after IPv6 decapsulation

CVE record · `CVE-2026-80976`

- **Identifiers:** `CVE-2026-80976`
- **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, 19:42 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: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before d1f0d353358987ca87f21d8956e2d2854951130d` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before 9ae92198c24d7dacd4070e2f34f6e1ed3a63061c` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before 96c74420ac92930a7e0f21770818544eee4a93d7` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before 2b154e96fcb3f01fd42765c64e0a56820fbc16eb` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before cfa186a0857a0f831dfca67b16bbc40ecfdf3280` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before c73fb911e02b9a766c950bc9707f3e3a96ffd702` (git)
  - affected: `d7a669dd2f8ba07a17423f4ad586dfc0379882f7 to before f967455fb2a5a2079b9eb5823e9ccf359174bf9f` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.14`
  - unaffected: `before 4.14` (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-2026-80976](https://www.cve.org/CVERecord?id=CVE-2026-80976)
- [NVD: CVE-2026-80976](https://nvd.nist.gov/vuln/detail/CVE-2026-80976)

### References from the CNA

- <https://git.kernel.org/stable/c/d1f0d353358987ca87f21d8956e2d2854951130d>
- <https://git.kernel.org/stable/c/a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8>
- <https://git.kernel.org/stable/c/9ae92198c24d7dacd4070e2f34f6e1ed3a63061c>
- <https://git.kernel.org/stable/c/96c74420ac92930a7e0f21770818544eee4a93d7>
- <https://git.kernel.org/stable/c/2b154e96fcb3f01fd42765c64e0a56820fbc16eb>
- <https://git.kernel.org/stable/c/cfa186a0857a0f831dfca67b16bbc40ecfdf3280>
- <https://git.kernel.org/stable/c/c73fb911e02b9a766c950bc9707f3e3a96ffd702>
- <https://git.kernel.org/stable/c/f967455fb2a5a2079b9eb5823e9ccf359174bf9f>

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-2026-80976>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-80976/>. Everything for agents: <https://agentprime.io/llms.txt>.