# tracing/histograms: Verify event_call identity when updating synth_event refcount

CVE record · `CVE-2026-99233`

- **Identifiers:** `CVE-2026-99233`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 2 Nov 2026
- **Updated:** 3 Nov 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 2 Nov 2026, 16:06 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: `4b147936fa509650beaf638b331573c23ba4d609 to before 381f543ed35c434d5b707369aa5dcd69ecf440af` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before 4472579bd1c83708b6fe623c870cdf728e947205` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before 23b4106e8b35823acc79e206c7745f55b9cfd78b` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before 06e816bed499fe47f39f12044382cc5d064485fb` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before 5597bb8db6855fcb97a67196d227fea359bcd81c` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4` (git)
  - affected: `4b147936fa509650beaf638b331573c23ba4d609 to before 3403d9bb27ebc3572bd048620746b4414e073bf9` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.17`
  - unaffected: `before 4.17` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.161 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.115 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.60 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.14 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3.1 to 7.3.*, inclusive` (semver)
  - unaffected: `7.4-rc1 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 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 2 Nov 2026, 16:06 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2026-99233)
- 2 Nov 2026, 16:12 UTC: First seen by agentprime
- 2 Nov 2026, 16:17 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-99233)

## Sources

- [CVE List: CVE-2026-99233](https://www.cve.org/CVERecord?id=CVE-2026-99233)
- [NVD: CVE-2026-99233](https://nvd.nist.gov/vuln/detail/CVE-2026-99233)

### References from the CNA

- <https://git.kernel.org/stable/c/381f543ed35c434d5b707369aa5dcd69ecf440af>
- <https://git.kernel.org/stable/c/4472579bd1c83708b6fe623c870cdf728e947205>
- <https://git.kernel.org/stable/c/23b4106e8b35823acc79e206c7745f55b9cfd78b>
- <https://git.kernel.org/stable/c/06e816bed499fe47f39f12044382cc5d064485fb>
- <https://git.kernel.org/stable/c/5597bb8db6855fcb97a67196d227fea359bcd81c>
- <https://git.kernel.org/stable/c/cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4>
- <https://git.kernel.org/stable/c/3403d9bb27ebc3572bd048620746b4414e073bf9>

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-2026-99233>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-99233/>. Everything for agents: <https://agentprime.io/llms.txt>.