# libceph: fix OOB read in decode_watchers() via missing bounds check

CVE record · `CVE-2026-80557`

- **Identifiers:** `CVE-2026-80557`
- **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:** 26 Aug 2026
- **Updated:** 16 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 26 Aug 2026, 14:37 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: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before 85479b7d65b4ebcb07fbbe57230976793974ab4a` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before 1c824e7c75bb4adf19553dd4ea944a5d83096be8` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before f161be39201eb5f9b1f58fb8f90b8a9cd3931eb6` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before eab3eeb68bfc639d74f27256f05546af5c4f787d` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before c59219a6b62d74936963983e5815524c3de8dd79` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before cb8246e5846dbbe34930903a90c7a90dd8e5910b` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before 7130d94846dadbb97b6b7f4d78a3a7bba6e3daa1` (git)
  - affected: `a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c to before 00ead17c7de137a692edee59f2772e6af687e8eb` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.9`
  - unaffected: `before 4.9` (semver)
  - unaffected: `5.10.267 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.218 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.185 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.154 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.106 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.47 to 6.18.*, inclusive` (semver)
  - unaffected: `7.1.10 to 7.1.*, inclusive` (semver)
  - unaffected: `7.2 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:** 0.0053, the 45th percentile, on 15 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 26 Aug 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-80557](https://www.cve.org/CVERecord?id=CVE-2026-80557)
- [NVD: CVE-2026-80557](https://nvd.nist.gov/vuln/detail/CVE-2026-80557)

### References from the CNA

- <https://git.kernel.org/stable/c/85479b7d65b4ebcb07fbbe57230976793974ab4a>
- <https://git.kernel.org/stable/c/1c824e7c75bb4adf19553dd4ea944a5d83096be8>
- <https://git.kernel.org/stable/c/f161be39201eb5f9b1f58fb8f90b8a9cd3931eb6>
- <https://git.kernel.org/stable/c/eab3eeb68bfc639d74f27256f05546af5c4f787d>
- <https://git.kernel.org/stable/c/c59219a6b62d74936963983e5815524c3de8dd79>
- <https://git.kernel.org/stable/c/cb8246e5846dbbe34930903a90c7a90dd8e5910b>
- <https://git.kernel.org/stable/c/7130d94846dadbb97b6b7f4d78a3a7bba6e3daa1>
- <https://git.kernel.org/stable/c/00ead17c7de137a692edee59f2772e6af687e8eb>

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-2026-80557>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-80557/>. Everything for agents: <https://agentprime.io/llms.txt>.