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CVE-2026-99233

tracing/histograms: Verify event_call identity when updating synth_event refcount

CVSS score

7.8

EPSS probability

—

Risk score

0.8

Published

2 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

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Vulnerability description

DayBreach AI Explanation

Verified against sources

Linux Kernel tracing/histograms Reference Count Vulnerability

Sources read

2

Source agreement

Tam uyum

Evidence confidence

%63

Short explanation

A vulnerability exists in the Linux kernel tracing/histograms subsystem where updating synthetic event reference counts fails to verify event_call identity. This allows operations on non-synthetic events to erroneously modify synthetic event reference counts.

Why does it matter?

This flaw can lead to a synthetic event being freed while an active action still holds a pointer to it, allowing local users to potentially compromise system integrity or confidentiality.

What should be done?

  • Follow official vendor advisories and updates.
  • Apply the relevant patch revisions.
Chain of evidence and sources2 verified claims

find_synth_event() fonksiyonu yalnızca olay temel adını karşılaştırdığı için sentetik olmayan olaylar sentetik olayların referans sayacını yanlışlıkla değiştirebilir.

S0 · daybreach-canonicalS1 · cvelistS2 · nvd

Söz konusu güvenlik açığı için CVSS taban puanı 7.8 olarak belirlenmiştir.

S0 · daybreach-canonicalS1 · cvelistS2 · nvd
Show the technical text from the sources

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.

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

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-99233 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1linuxLinux View
2linuxLinux View
Total affected vendors: 1|Products: 2

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
7.8CVSS V3_1HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVE CNA
7.8CVSS V31HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-99233 is associated with the following CWEs:

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CWE-20: Improper Input Validation

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-99233 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureYerel erişim
PermissionsLow
UserGerekmiyor

Official Sources and Advisories

https://git.kernel.org/stable/c/381f543ed35c434d5b707369aa5dcd69ecf440afvendor-advisoryhttps://git.kernel.org/stable/c/4472579bd1c83708b6fe623c870cdf728e947205vendor-advisoryhttps://git.kernel.org/stable/c/23b4106e8b35823acc79e206c7745f55b9cfd78bvendor-advisoryhttps://git.kernel.org/stable/c/06e816bed499fe47f39f12044382cc5d064485fbvendor-advisoryhttps://git.kernel.org/stable/c/5597bb8db6855fcb97a67196d227fea359bcd81cvendor-advisoryhttps://git.kernel.org/stable/c/cf4e31d5da80fae4c9cdbe7af55b7c3ad213f0e4vendor-advisory

CVSS Vector Radar Chart

7.8 / 10
Attack VectorLocalComplexityLowPrivilegesLowUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

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CVE-2026-99233 · tracing/histograms: Verify event_call…