# ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()

CVE record · `CVE-2026-89503`

- **Identifiers:** `CVE-2026-89503`
- **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, 19:43 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: `bce761d757452ba5eb77e11fecc37a04b67494e7 to before 2313ff69bd237aad264a5913907f374f958335a2` (git)
  - affected: `bce761d757452ba5eb77e11fecc37a04b67494e7 to before 2dc510957fe8fd098ab3c3147ebdf34d00cd2734` (git)
  - affected: `bce761d757452ba5eb77e11fecc37a04b67494e7 to before 53106e9262a310ef2c9a9321168c03705940c678` (git)
  - affected: `bce761d757452ba5eb77e11fecc37a04b67494e7 to before e743527c5bfdceda1095bc0a9e596e2aebb6a9c3` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `6.8`
  - unaffected: `before 6.8` (semver)
  - unaffected: `6.12.112 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:** 0.0017, the 6th 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-2026-89503](https://www.cve.org/CVERecord?id=CVE-2026-89503)
- [NVD: CVE-2026-89503](https://nvd.nist.gov/vuln/detail/CVE-2026-89503)

### References from the CNA

- <https://git.kernel.org/stable/c/2313ff69bd237aad264a5913907f374f958335a2>
- <https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734>
- <https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678>
- <https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3>

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-2026-89503>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89503/>. Everything for agents: <https://agentprime.io/llms.txt>.