---
title: "CVE-2026-99233: Linux Kernel - Broken Access Control"
description: "Linux kernel contains a broken access control vulnerability caused by improper verification of event_call identity in tracing/histograms, letting attackers cause use-after-free by manipulating synthetic event reference counts, exploit requires histogram registration on non-synthetic events with matching basename."
url: https://panop.io/threat-heartbeat/CVE-2026-99233/
---

# CVE-2026-99233 Linux Kernel - Broken Access Control

Linux kernel contains a broken access control vulnerability caused by improper verification of event\_call identity in tracing/histograms, letting attackers cause use-after-free by manipulating synthetic event reference counts, exploit requires histogram registration on non-synthetic events with matching basename.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-99233)

## Details

Type

Broken Access Control

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

2 November 2026

Updated

3 November 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for event\_call identity verification.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-99233](https://nvd.nist.gov/vuln/detail/CVE-2026-99233)
- [https://git.kernel.org/stable/c/cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4](https://git.kernel.org/stable/c/cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4)
- [https://git.kernel.org/stable/c/06e816bed499fe47f39f12044382cc5d064485fb](https://git.kernel.org/stable/c/06e816bed499fe47f39f12044382cc5d064485fb)
- [https://git.kernel.org/stable/c/23b4106e8b35823acc79e206c7745f55b9cfd78b](https://git.kernel.org/stable/c/23b4106e8b35823acc79e206c7745f55b9cfd78b)
- [https://git.kernel.org/stable/c/381f543ed35c434d5b707369aa5dcd69ecf440af](https://git.kernel.org/stable/c/381f543ed35c434d5b707369aa5dcd69ecf440af)
- [https://git.kernel.org/stable/c/4472579bd1c83708b6fe623c870cdf728e947205](https://git.kernel.org/stable/c/4472579bd1c83708b6fe623c870cdf728e947205)
- [https://git.kernel.org/stable/c/5597bb8db6855fcb97a67196d227fea359bcd81c](https://git.kernel.org/stable/c/5597bb8db6855fcb97a67196d227fea359bcd81c)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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