VulnerabilityPublished 16 Sep 2026Updated 30 Oct 2026

CVE-2026-89956: Linux kernel · s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects

Source GCVE Database

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Authoritative record:CVE-2026-89956· High

Not known to be exploited · fixed in 647916988272fe5ecb4bb30cd02b51af9960618a : patch Linux kernel soon.

Data as of 30 Oct 2026, 19:20 UTC

Severity

High

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

Thin evidence

One scorer or none

Patch: Available – fixed in 647916988272fe5ecb4bb30cd02b51af9960618a, 530ee1cc71562b6799b9ece187b6c1b757a2c6fa, 22dc712c170efc1a549e3f872467c880be995ac7 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Sep 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.

ghsa-vvfx-87j6-h3vv

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 647916988272fe5ecb4bb30cd02b51af9960618a	Fixed in 647916988272fe5ecb4bb30cd02b51af9960618a
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 530ee1cc71562b6799b9ece187b6c1b757a2c6fa	Fixed in 530ee1cc71562b6799b9ece187b6c1b757a2c6fa
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 22dc712c170efc1a549e3f872467c880be995ac7	Fixed in 22dc712c170efc1a549e3f872467c880be995ac7
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 7fa61c29850d05e40ca9ed41bfdf57673023f581	Fixed in 7fa61c29850d05e40ca9ed41bfdf57673023f581
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 3ea443510739468238324234eaab0d37922283f5	Fixed in 3ea443510739468238324234eaab0d37922283f5
LinuxLinux	Affected ≥ 2c1ee8983aa377fef4f725162f4f3aa5f9575d4a, < 0fd74477d05743d4cd9b25a3b667daa278d53b93	Fixed in 0fd74477d05743d4cd9b25a3b667daa278d53b93

AI-suggested

A fix has been implemented in the Linux kernel to ensure the matrix_dev->guests_lock mutex is held when accessing or modifying the ap_matrix_mdev list. Users should update to a Linux kernel version that includes this fix. No additional mitigation steps are required beyond applying the official kernel patch.

Description

A concurrency issue in the Linux kernel's s390 vfio-ap driver was fixed by ensuring proper locking when accessing the list of ap_matrix_mdev objects. The vulnerability involved missing mutex protection leading to potential kernel memory corruption or use-after-free conditions during concurrent modifications of the device list.

References

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