# ceph: fix UAF in \_\_kick_flushing_caps() on cf entry freed during unlock

CVE record · `CVE-2026-89655`

- **Identifiers:** `CVE-2026-89655`
- **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, 19:45 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: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 091137821e1fc88f37e15201abf055c9494ddc61` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 01542430081014d80fc9e70e92d6647432ddb7fc` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 23eb34a53a53cb1a6dab1eeee830633207ac158d` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 19f16f04c2b014a7dd214dc1e42557d8530b16f3` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 2701431aa3cc8b23efe6890182e7b04f5e76fab5` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before fe46746087b5b9c5bb2d022df6c7819218494ced` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 2dba24dcd5050be4b7b119e6f0b01f62203b5d26` (git)
  - affected: `e4500b5e35c213e0f97be7cb69328c0877203a79 to before 7af4c4f01305b0935adf6d4301b1ec407025485d` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.8`
  - unaffected: `before 4.8` (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-2026-89655](https://www.cve.org/CVERecord?id=CVE-2026-89655)
- [NVD: CVE-2026-89655](https://nvd.nist.gov/vuln/detail/CVE-2026-89655)

### References from the CNA

- <https://git.kernel.org/stable/c/091137821e1fc88f37e15201abf055c9494ddc61>
- <https://git.kernel.org/stable/c/01542430081014d80fc9e70e92d6647432ddb7fc>
- <https://git.kernel.org/stable/c/23eb34a53a53cb1a6dab1eeee830633207ac158d>
- <https://git.kernel.org/stable/c/19f16f04c2b014a7dd214dc1e42557d8530b16f3>
- <https://git.kernel.org/stable/c/2701431aa3cc8b23efe6890182e7b04f5e76fab5>
- <https://git.kernel.org/stable/c/fe46746087b5b9c5bb2d022df6c7819218494ced>
- <https://git.kernel.org/stable/c/2dba24dcd5050be4b7b119e6f0b01f62203b5d26>
- <https://git.kernel.org/stable/c/7af4c4f01305b0935adf6d4301b1ec407025485d>

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-2026-89655>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89655/>. Everything for agents: <https://agentprime.io/llms.txt>.