VulnerabilityPublished 28 Oct 2026

CVE-2026-99156: Linux kernel · scsi: st: Fix use-after-free race between st_remove() and st_open()

Source GCVE Database

Authoritative record:CVE-2026-99156

Not known to be exploited · fixed in a1647b653549ff29f0422a63eabf329b842f3822 : patch Linux kernel soon.

Data as of 28 Oct 2026, 14:02 UTC

Severity

High

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

Patch: Available – fixed in a1647b653549ff29f0422a63eabf329b842f3822, 71caf7f84bd62a4bf91cc95abd2de690afb8d15f, 18a0e3733ce38718688e813e5e2d1106bd4830e5

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-3wp3-5585-mc8q

What to do

Upgrade Linux kernel to a1647b653549ff29f0422a63eabf329b842f3822, 71caf7f84bd62a4bf91cc95abd2de690afb8d15f or 18a0e3733ce38718688e813e5e2d1106bd4830e5.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 6c648d95a6af4a79241a916871df17c84c68ea20, < a1647b653549ff29f0422a63eabf329b842f3822	Fixed in a1647b653549ff29f0422a63eabf329b842f3822
LinuxLinux	Affected ≥ 6c648d95a6af4a79241a916871df17c84c68ea20, < 71caf7f84bd62a4bf91cc95abd2de690afb8d15f	Fixed in 71caf7f84bd62a4bf91cc95abd2de690afb8d15f
LinuxLinux	Affected ≥ 6c648d95a6af4a79241a916871df17c84c68ea20, < 18a0e3733ce38718688e813e5e2d1106bd4830e5	Fixed in 18a0e3733ce38718688e813e5e2d1106bd4830e5
LinuxLinux	Affected =3.7	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to reorder operations in st_remove() to prevent the use-after-free race. Users should update to the fixed kernel version once available. No additional mitigation is required beyond applying the official patch.

Description

A use-after-free race condition was identified and fixed in the Linux kernel's SCSI tape driver (st). The issue occurs due to improper ordering in st_remove() where the scsi_tape structure could be freed while still accessible, leading to potential memory corruption when accessed concurrently by st_open(). The fix ensures the tape index is removed before dropping the reference, preventing access to freed memory.

Impact

This vulnerability can lead to a kernel use-after-free condition, potentially causing system instability or crashes due to memory corruption. However, no known exploits in the wild have been reported. The impact is limited to local kernel memory safety and stability.

Summary

The vulnerability in the Linux kernel's SCSI tape driver (st) involves a use-after-free race condition between st_remove() and st_open(). st_remove() previously dropped the probe reference on the scsi_tape structure after removing its index from st_index_idr, allowing a concurrent st_open() to access a freed structure. This could cause a kernel slab-use-after-free error detected by KASAN. The fix reorders operations to remove the tape index from the idr before dropping the reference, ensuring that concurrent lookups either hold a valid reference or fail cleanly, preventing use-after-free.

References

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