VulnerabilityPublished 28 Oct 2026

CVE-2026-99140: Linux kernel · tracing: Fix hist trigger timestamps for buffered events

Source GCVE Database

Authoritative record:CVE-2026-99140

Not known to be exploited · fixed in 9414ca3b99e5a7f1f3bf51c2a01b383e1b355dd0 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 14:13 UTC

Severity

Low

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

Patch: Available – fixed in 9414ca3b99e5a7f1f3bf51c2a01b383e1b355dd0, 89e90b16aadd6e66bd0323bc8dfc76a62e756b57, 09c7cce2e59e6b3b1807520bcb1980c561f15d1e

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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-jpcj-q7f6-fxvj

What to do

Upgrade Linux kernel to 9414ca3b99e5a7f1f3bf51c2a01b383e1b355dd0, 89e90b16aadd6e66bd0323bc8dfc76a62e756b57 or 09c7cce2e59e6b3b1807520bcb1980c561f15d1e.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b94bc80df64823e676b506f8de7dcf6a688d681e, < 9414ca3b99e5a7f1f3bf51c2a01b383e1b355dd0	Fixed in 9414ca3b99e5a7f1f3bf51c2a01b383e1b355dd0
LinuxLinux	Affected ≥ b94bc80df64823e676b506f8de7dcf6a688d681e, < 89e90b16aadd6e66bd0323bc8dfc76a62e756b57	Fixed in 89e90b16aadd6e66bd0323bc8dfc76a62e756b57
LinuxLinux	Affected ≥ b94bc80df64823e676b506f8de7dcf6a688d681e, < 09c7cce2e59e6b3b1807520bcb1980c561f15d1e	Fixed in 09c7cce2e59e6b3b1807520bcb1980c561f15d1e
LinuxLinux	Affected =5.13	Fixed in–
Debiandebian/linux`pkg:deb/debian/linux`Other threats	Affected =5.13	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 address this issue by using the tracing_event_time_stamp() API for buffered events in hist triggers. Users should update to the fixed kernel version once available. No other mitigation actions are specified.

Description

A Linux kernel vulnerability involving tracing hist trigger timestamps for buffered events has been fixed. The issue caused a WARN_ON_ONCE warning due to a race condition when hist triggers accessed buffered events with zero committing count, leading to incorrect timestamp handling. The fix uses a dedicated API to provide accurate timestamps for buffered events, preventing the warning and ensuring correct event timing.

Impact

The vulnerability causes a kernel warning (WARN_ON_ONCE) that may indicate instability or unexpected behavior in the tracing subsystem when hist triggers race with buffered events. There is no indication of security impact such as privilege escalation or denial of service. No known exploits in the wild have been reported.

Summary

The vulnerability in the Linux kernel tracing subsystem was triggered when a hist trigger accessed buffered events that had not incremented the committing count due to filter buffering. This caused a WARN_ON_ONCE(!nest) warning in ring_buffer_event_time_stamp() because the committing count was zero. The root cause was that events with filters but without attached hist triggers were buffered temporarily without incrementing cpu_buffer->committing. The fix involved using the tracing_event_time_stamp() API in hist_field_timestamp() to return the current ring buffer timestamp for buffered events, avoiding bogus timestamps and the warning.

References

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