CVE-2026-31592VulnerabilityPublished 2 Apr 2026Updated 28 Jun 2026

Microsoft · KVM: SEV: Protect all of sev_mem_enc_register_region() with kvm->lock

Affects MicrosoftSource GCVE Database

Authoritative record:CVE-2026-31592

Not known to be exploited · fixed in b6408b6cec5df76a165575777800ef2aba12b109 : update Microsoft when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b6408b6cec5df76a165575777800ef2aba12b109, ab725ac3022469ecd4d7aa7d5646712e98b249d8, 777a8ebd2da3529a455af022ed929408fdbb161f +3

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Apr 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.

microsoft-security-response-ce

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < b6408b6cec5df76a165575777800ef2aba12b109	Fixed in b6408b6cec5df76a165575777800ef2aba12b109
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < ab725ac3022469ecd4d7aa7d5646712e98b249d8	Fixed in ab725ac3022469ecd4d7aa7d5646712e98b249d8
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < 777a8ebd2da3529a455af022ed929408fdbb161f	Fixed in 777a8ebd2da3529a455af022ed929408fdbb161f
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < 35a0963d361f98bba798fd15d229dcb166c04684	Fixed in 35a0963d361f98bba798fd15d229dcb166c04684
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < 25c85d5831201391fb920d51067c6d93cce55348	Fixed in 25c85d5831201391fb920d51067c6d93cce55348
LinuxLinux	Affected ≥ 1e80fdc09d121d8327cdf62eefbb5abadddca792, < 0ff93ff0ba82e9511770e175fa50682a1ab14fb6	Fixed in 0ff93ff0ba82e9511770e175fa50682a1ab14fb6

Description

CVE-2026-31592 is a vulnerability related to the KVM SEV (Secure Encrypted Virtualization) feature where the function sev_mem_enc_register_region() is not fully protected by the kvm->lock. This could potentially lead to concurrency issues in the management of encrypted memory regions. The vulnerability affects Microsoft products with versions 2.0 and 3.0. No CVSS score is provided, and there is no indication of known exploits in the wild or available patches.

Impact

The impact could involve potential race conditions or inconsistent memory encryption state in virtualized environments using KVM SEV, which might affect confidentiality or integrity of virtual machine memory. However, no specific exploitation or impact details are provided, and no known exploits are reported.

Summary

This vulnerability involves insufficient locking in the KVM SEV implementation, specifically that the entire sev_mem_enc_register_region() function is not protected by the kvm->lock, which is intended to serialize access to KVM structures. The lack of full locking could lead to race conditions or inconsistent state in the handling of encrypted memory regions within virtual machines. The affected products are Microsoft versions 2.0 and 3.0. No detailed technical exploitation or impact scenarios are provided in the source data.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Jun 2026, 22:58 UTC

Technical details

References

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