VulnerabilityPublished 22 Aug 2026Updated 21 Oct 2026

CVE-2026-74729: Linux kernel · soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in b87c0d24386ed5106feac12034fe09d893ccb469 : patch Linux kernel soon.

Data as of 26 Oct 2026, 21:36 UTC

Severity

High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b87c0d24386ed5106feac12034fe09d893ccb469, afe2527eae0b51d5e8ddd77293afab3a5a1311a4, 868c478abce858135db3eb65548a577e4b6747ac +2

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Aug 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 3772e5da445420543b25825ac2b5971f3743f6e8, < b87c0d24386ed5106feac12034fe09d893ccb469	Fixed in b87c0d24386ed5106feac12034fe09d893ccb469
LinuxLinux	Affected ≥ 3772e5da445420543b25825ac2b5971f3743f6e8, < afe2527eae0b51d5e8ddd77293afab3a5a1311a4	Fixed in afe2527eae0b51d5e8ddd77293afab3a5a1311a4
LinuxLinux	Affected ≥ 3772e5da445420543b25825ac2b5971f3743f6e8, < 868c478abce858135db3eb65548a577e4b6747ac	Fixed in 868c478abce858135db3eb65548a577e4b6747ac
LinuxLinux	Affected ≥ 3772e5da445420543b25825ac2b5971f3743f6e8, < 131ab677b03349a5ae48da8722ec7075b37ec66e	Fixed in 131ab677b03349a5ae48da8722ec7075b37ec66e
LinuxLinux	Affected ≥ 3772e5da445420543b25825ac2b5971f3743f6e8, < 1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f	Fixed in 1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f
LinuxLinux	Affected =4.19	Fixed in–

AI-suggested

A fix is available and has been applied in multiple Linux kernel commits. Users should update to a Linux kernel version that includes these fixes. No additional mitigation is required beyond applying the official patch.

Description

CVE-2026-74729 is a vulnerability in the Linux kernel's aspeed LPC snoop driver where concurrent access to a kernel FIFO buffer is not properly synchronized. This can cause a usercopy overflow during read operations, potentially leading to kernel memory exposure and a kernel BUG. The issue is fixed by serializing access to the FIFO with a spinlock to prevent concurrent modifications.

Impact

The vulnerability can cause a usercopy overflow in kernel memory, leading to kernel memory exposure attempts and kernel crashes (kernel BUG). This could affect system stability and security by exposing kernel memory contents or causing denial of service via kernel panic.

Summary

The Linux kernel aspeed LPC snoop driver had a concurrency flaw in its FIFO buffer handling. The function put_fifo_with_discard() acted as both producer and consumer on the kfifo without proper synchronization with snoop_file_read(), which also consumes from the FIFO. On SMP systems, this race condition could cause the FIFO's (in - out) count to exceed the buffer size, bypassing clamps in __kfifo_to_user() and causing kfifo_copy_to_user() to copy beyond the allocated kmalloc-2k buffer. This leads to a usercopy overflow, kernel memory exposure detection, and a kernel BUG. The fix involves adding a per-channel spinlock to serialize FIFO access between the IRQ handler and file reader, with compiler-enforced locking annotations.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 21:36 UTC

Technical details

References

Community reviews

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