# ring-buffer: Fix subbuf resize race with ring buffer readers

CVE record · `CVE-2026-89771`

- **Identifiers:** `CVE-2026-89771`
- **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, 19:47 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: `f9b94daa542a8d2532f0930f01cd9aec2d19621b to before 6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9` (git)
  - affected: `f9b94daa542a8d2532f0930f01cd9aec2d19621b to before 50f4a793c4ff24826efb0ac700989a5063cc53df` (git)
  - affected: `f9b94daa542a8d2532f0930f01cd9aec2d19621b to before 0c7c517827a453128a8f58bfd849546a29813b27` (git)
  - affected: `f9b94daa542a8d2532f0930f01cd9aec2d19621b to before 8a5f63637890f03177146efddaba5ec7a1b4d61f` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.8`
  - unaffected: `before 6.8` (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:** 0.0012, the 1st 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-2026-89771](https://www.cve.org/CVERecord?id=CVE-2026-89771)
- [NVD: CVE-2026-89771](https://nvd.nist.gov/vuln/detail/CVE-2026-89771)

### References from the CNA

- <https://git.kernel.org/stable/c/6d666f0b8b36c0765cf19fbe6de5a7ba5a73aad9>
- <https://git.kernel.org/stable/c/50f4a793c4ff24826efb0ac700989a5063cc53df>
- <https://git.kernel.org/stable/c/0c7c517827a453128a8f58bfd849546a29813b27>
- <https://git.kernel.org/stable/c/8a5f63637890f03177146efddaba5ec7a1b4d61f>

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-2026-89771>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89771/>. Everything for agents: <https://agentprime.io/llms.txt>.