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CVE-2026-99233

tracing/histograms: Verify event_call identity when updating synth_event refcount

No exploitation reported by the sources we read.

  • Published2026-11-02

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

In the Linux kernel, the following vulnerability has been resolved: tracing/histograms: Verify event_call identity when updating synth_event refcount In event_hist_trigger_parse() and hist_unreg_all(), the histogram registration and unregistration paths look up find_synth_event() using trace_event_name(file->event_call) and adjust se->ref if a match is found. Because find_synth_event() only compares the event basename, registering or removing a histogram on a non-synthetic trace event whose basename matches a synthetic event erroneously modifies the synthetic event's reference count. If a histogram is registered on the non-synthetic event before the synthetic event is created and removed afterwards, se->ref is decremented without a matching increment, allowing the synthetic event to be freed while an active histogram action still holds a pointer to it. Introduce find_synth_event_call() to verify that &se->call matches file->event_call before adjusting se->ref.

Timeline

dates in UTC
  1. 2026-11-0216:06CVE publishedCNA

Observed activity

isMalicious corpus · updated 2026-11-02 15:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-99233?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-99233?format=csv
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Versions per branch

Products declared by the CNA

As Linux, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • Linuxother versions: not affected

    https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

    Affected
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < 381f543ed35c434d5b707369aa5dcd69ecf440affixed in 381f543ed35c434d5b707369aa5dcd69ecf440afgit
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < 4472579bd1c83708b6fe623c870cdf728e947205fixed in 4472579bd1c83708b6fe623c870cdf728e947205git
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < 23b4106e8b35823acc79e206c7745f55b9cfd78bfixed in 23b4106e8b35823acc79e206c7745f55b9cfd78bgit
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < 06e816bed499fe47f39f12044382cc5d064485fbfixed in 06e816bed499fe47f39f12044382cc5d064485fbgit
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < 5597bb8db6855fcb97a67196d227fea359bcd81cfixed in 5597bb8db6855fcb97a67196d227fea359bcd81cgit
    • ≥ 4b147936fa509650beaf638b331573c23ba4d609, < cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4fixed in cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4git
  • Linuxother versions: affected

    https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

    Affected
    • = 4.17no fix stated

    Not affected < 4.17 · ≥ 6.1.191, ≤ 6.1.* · ≥ 6.6.161, ≤ 6.6.* · ≥ 6.12.115, ≤ 6.12.* · ≥ 6.18.60, ≤ 6.18.* · ≥ 7.2.14, ≤ 7.2.* · ≥ 7.3.1, ≤ 7.3.*

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-02

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-99233 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE record2026-11-02
  • CNACVSS 3.17.82026-11-02

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published
2026-11-02

Frequently asked questions

What is CVE-2026-99233?

In the Linux kernel, the following vulnerability has been resolved: tracing/histograms: Verify event_call identity when updating synth_event refcount In event_hist_trigger_parse() and hist_unreg_all(), the histogram registration and unregistration paths look up find_synth_event() using trace_event_name(file->event_call) and adjust se->ref if a match is found. Because find_synth_event() only compares the event basename, registering or removing a histogram on a non-synthetic trace event whose basename matches a synthetic event erroneously modifies the synthetic event's reference count. If a histogram is registered on the non-synthetic event before the synthetic event is created and removed afterwards, se->ref is decremented without a matching increment, allowing the synthetic event to be freed while an active histogram action still holds a pointer to it. Introduce find_synth_event_call() to verify that &se->call matches file->event_call before adjusting se->ref.

Is CVE-2026-99233 actively exploited?

Active exploitation of CVE-2026-99233 has not been confirmed.

What is the CVSS score for CVE-2026-99233?

CVE-2026-99233 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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