# netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels

CVE record · `CVE-2026-23274`

- **Identifiers:** `CVE-2026-23274`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** Linux
- **Weakness (CWE):** [CWE-758](https://cwe.mitre.org/data/definitions/758.html)
- **Tags:** [CWE-758](https://agentprime.io/advisories/tag/cwe-758.md)
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 20 Mar 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 20 Mar 2026, 08:08 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: `68983a354a655c35d3fb204489d383a2a051fda7 to before 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before 144f88054ba0180467356f40895bd660b5dceeec` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before 28c7cfaf0c0ab17cbd7754092116fd1af45271f9` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before 54080355999381fed4a26129579a5765bab87491` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before 5e7ece24c5cb75a60402aad4d803c7898ea40aa9` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before f228b9ae2a7e84d1153616d8e71c4236cb1f1309` (git)
  - affected: `68983a354a655c35d3fb204489d383a2a051fda7 to before 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `5.7`
  - unaffected: `before 5.7` (semver)
  - unaffected: `5.10.253 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.203 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.167 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.130 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.78 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.19 to 6.18.*, inclusive` (semver)
  - unaffected: `6.19.9 to 6.19.*, inclusive` (semver)
  - unaffected: `7.0 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:** 0.0018, the 7th percentile, on 5 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 20 Mar 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-23274](https://www.cve.org/CVERecord?id=CVE-2026-23274)
- [NVD: CVE-2026-23274](https://nvd.nist.gov/vuln/detail/CVE-2026-23274)

### References from the CNA

- <https://git.kernel.org/stable/c/32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44>
- <https://git.kernel.org/stable/c/144f88054ba0180467356f40895bd660b5dceeec>
- <https://git.kernel.org/stable/c/28c7cfaf0c0ab17cbd7754092116fd1af45271f9>
- <https://git.kernel.org/stable/c/54080355999381fed4a26129579a5765bab87491>
- <https://git.kernel.org/stable/c/5e7ece24c5cb75a60402aad4d803c7898ea40aa9>
- <https://git.kernel.org/stable/c/f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1>
- <https://git.kernel.org/stable/c/f228b9ae2a7e84d1153616d8e71c4236cb1f1309>
- <https://git.kernel.org/stable/c/329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf>

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-2026-23274>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-23274/>. Everything for agents: <https://agentprime.io/llms.txt>.