VulnerabilityPublished 25 Mar 2026Updated 30 Oct 2026

CVE-2026-23374: Linux kernel · blktrace: fix __this_cpu_read/write in preemptible context

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e5584932ac1dacc182c430d09e2b5490d1d4372b : update Linux kernel when convenient.

Data as of 30 Oct 2026, 12:48 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Patch: Available – fixed in e5584932ac1dacc182c430d09e2b5490d1d4372b, da46b5dfef48658d03347cda21532bcdbb521e67, aaba6ee63ba65b026401c94e2dd16b9f6e895934 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Mar 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 30 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.
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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < e5584932ac1dacc182c430d09e2b5490d1d4372b	Fixed in e5584932ac1dacc182c430d09e2b5490d1d4372b
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < da46b5dfef48658d03347cda21532bcdbb521e67	Fixed in da46b5dfef48658d03347cda21532bcdbb521e67
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < aaba6ee63ba65b026401c94e2dd16b9f6e895934	Fixed in aaba6ee63ba65b026401c94e2dd16b9f6e895934
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < 59efa088752b1c380a0475974679850cc8aef907	Fixed in 59efa088752b1c380a0475974679850cc8aef907
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < 37e86414cc9989344de82d2a658a095f8d5e71d9	Fixed in 37e86414cc9989344de82d2a658a095f8d5e71d9
LinuxLinux	Affected ≥ 7ffbd48d5cab22bcd1120eb2349db1319e2d827a, < 6e5c3ddf17a2cb1722301bbbd15655fcc20ed1ce	Fixed in 6e5c3ddf17a2cb1722301bbbd15655fcc20ed1ce

AI-suggested

A fix is available and has been applied in specific Linux kernel commits. Users should update their Linux kernel to a version that includes these fixes to resolve the issue. No additional mitigation actions are indicated.

Description

CVE-2026-23374 is a vulnerability in the Linux kernel's blktrace component where __this_cpu_read() and __this_cpu_write() are incorrectly used in a preemptible context. This misuse can cause kernel bugs and crashes when tracing block I/O operations from process context with preemption enabled. The issue has been fixed in specific Linux kernel commits.

Impact

The vulnerability causes kernel bugs and potential crashes due to unsafe access to per-CPU variables with preemption enabled. This can lead to system instability and trace corruption during block I/O tracing operations. There is no indication of remote exploitability or privilege escalation from the provided data.

Summary

The vulnerability involves the blktrace subsystem in the Linux kernel where the functions __this_cpu_read() and __this_cpu_write() are called in a context where preemption is enabled, which is unsafe. Specifically, tracing_record_cmdline() uses these functions on a per-CPU variable and asserts that preemption is disabled, but __blk_add_trace() calls this function early in the blk_tracer path from process context with preemption enabled. This leads to kernel BUGs and trace corruption as demonstrated by failing blktrace tests and kernel logs showing BUG messages. The problem also affects other blk_add_trace_* paths. The issue has been resolved in multiple kernel commits identified by their hashes.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 12:48 UTC

Technical details

References

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