VulnerabilityPublished 2 Nov 2026

CVE-2026-99232: Linux kernel · tracing/syscalls: Use copy_from_user for the faultable syscall buffer

Source GCVE Database

Authoritative record:CVE-2026-99232· Medium

Not known to be exploited : upgrade to e33e2718c62a602001ab549642a1aed0be797105 or 041d1a568a11a7ed7415ef1408d0c65041c1ad69 when convenient.

Data as of 2 Nov 2026, 19:30 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in e33e2718c62a602001ab549642a1aed0be797105, 041d1a568a11a7ed7415ef1408d0c65041c1ad69

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-2w2h-c9pf-xxjf

What to do

Upgrade Linux kernel to e33e2718c62a602001ab549642a1aed0be797105 or 041d1a568a11a7ed7415ef1408d0c65041c1ad69.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ baa031b7bd2ce7502339174a42974321859ecd6a, < e33e2718c62a602001ab549642a1aed0be797105	Fixed in e33e2718c62a602001ab549642a1aed0be797105
LinuxLinux	Affected ≥ baa031b7bd2ce7502339174a42974321859ecd6a, < 041d1a568a11a7ed7415ef1408d0c65041c1ad69	Fixed in 041d1a568a11a7ed7415ef1408d0c65041c1ad69
LinuxLinux	Affected =6.19	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =6.19	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to replace __copy_from_user() with copy_from_user() in syscall_copy_user_array(). Users should apply the official kernel updates containing this fix once available. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's syscall tracing mechanism was fixed by changing the buffer copy method from __copy_from_user() to copy_from_user(). This ensures that non-user addresses are rejected and faulted syscalls are properly recorded. The issue could pose a security concern on systems that overly trust the perf subsystem.

Impact

The vulnerability could allow invalid or non-user memory addresses to be accepted in syscall buffers without proper fault detection, potentially leading to incorrect syscall tracing behavior. This may affect the security posture of systems that rely heavily on perf for monitoring or security decisions. No known exploits in the wild have been reported.

Summary

The Linux kernel's syscall_copy_user_array() function previously used __copy_from_user() to copy the buffer argument of faultable syscalls such as write and pwrite64. This function skips the access_ok() check, potentially allowing non-user addresses to be accepted without faulting. The fix replaces __copy_from_user() with copy_from_user(), which performs the access_ok() check, rejecting invalid addresses and recording the syscall as faulted. This correction mitigates a security concern related to trusting perf on affected systems.

References

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