# ip6_tunnel: use skb_cow_head() in ip6_tnl_xmit()

CVE record · `CVE-2026-89563`

- **Identifiers:** `CVE-2026-89563`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **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, 19:44 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.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before 6e8eff8ed13b14708bc39f170144eacde494aac6` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before dc1a319a4815c074914e2812e0e9cd0164ca682b` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before 629d5557e635cdbc109a14ed913ba5a540e3f79a` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before defa0adeff132cc90ed66915b9a104d9393e1e54` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before 37df5bc6b5ccad88c2faa0f5466f150178882b74` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before b36dfd6e8cff00cea81c11cc0af88d1564763461` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before 8fc56ca49fc0ee1725b55c67bb43ab0dd01f3f52` (git)
  - affected: `058214a4d1dfefed9f01a277fadd3590acb5f990 to before 87f21b59ddc618eff9670c174842964ad65fdade` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.7`
  - unaffected: `before 4.7` (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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0014, the 3rd 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-2026-89563](https://www.cve.org/CVERecord?id=CVE-2026-89563)
- [NVD: CVE-2026-89563](https://nvd.nist.gov/vuln/detail/CVE-2026-89563)

### References from the CNA

- <https://git.kernel.org/stable/c/6e8eff8ed13b14708bc39f170144eacde494aac6>
- <https://git.kernel.org/stable/c/dc1a319a4815c074914e2812e0e9cd0164ca682b>
- <https://git.kernel.org/stable/c/629d5557e635cdbc109a14ed913ba5a540e3f79a>
- <https://git.kernel.org/stable/c/defa0adeff132cc90ed66915b9a104d9393e1e54>
- <https://git.kernel.org/stable/c/37df5bc6b5ccad88c2faa0f5466f150178882b74>
- <https://git.kernel.org/stable/c/b36dfd6e8cff00cea81c11cc0af88d1564763461>
- <https://git.kernel.org/stable/c/8fc56ca49fc0ee1725b55c67bb43ab0dd01f3f52>
- <https://git.kernel.org/stable/c/87f21b59ddc618eff9670c174842964ad65fdade>

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-2026-89563>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89563/>. Everything for agents: <https://agentprime.io/llms.txt>.