Linux Kernel up to 6.18.43/7.1.7 mshv mshv_irqfd_deassign locking

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.00

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.18.43/7.1.7. This affects the function mshv_irqfd_deassign of the component mshv. Performing a manipulation results in locking. This vulnerability was named CVE-2026-80896. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.43/7.1.7. It has been classified as very critical. This affects the function mshv_irqfd_deassign of the component mshv. The manipulation with an unknown input leads to a locking vulnerability. CWE is classifying the issue as CWE-667. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mshv: Fix race in mshv_irqfd_deassign mshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list require pt->pt_irqfds_lock to be held, but mshv_irqfd_deassign() omits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(), which does take the lock before calling mshv_irqfd_deactivate(). Additionally, mshv_irqfd_deactivate() uses hlist_del() which poisons the node pointers rather than resetting them. Since mshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev == NULL), a poisoned node still appears active. If a concurrent path calls mshv_irqfd_deactivate() again on the same irqfd, the guard fails to prevent a double hlist_del() on poisoned pointers. Fix both issues: - Add the missing spin_lock_irq/spin_unlock_irq around the list traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release(). - Use hlist_del_init() instead of hlist_del() so the node is properly marked as unhashed after removal, making the is_active guard reliable.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-80896 since 08/26/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/04/2026).

Upgrading to version 6.18.44 or 7.1.8 eliminates this vulnerability. Applying the patch 72a90ce4918b5a2d4820fe20677ba9af780d8826/4529a41a675b96e0f876eef1cc93a31a57cb4d18/0762262ac3e70f65b3bb843fe892f8bac1562d08 is able to eliminate this problem.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Locking
CWE: CWE-667
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.44/7.1.8
Patch: 72a90ce4918b5a2d4820fe20677ba9af780d8826/4529a41a675b96e0f876eef1cc93a31a57cb4d18/0762262ac3e70f65b3bb843fe892f8bac1562d08

Timelineinfo

08/26/2026 CVE reserved
09/04/2026 +9 days Advisory disclosed
09/04/2026 +0 days VulDB entry created
09/04/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80896 (🔒)
GCVE (CVE): GCVE-0-2026-80896
GCVE (VulDB): GCVE-100-399093

Entryinfo

Created: 09/04/2026 19:34
Changes: 09/04/2026 19:34 (59)
Complete: 🔍
Cache ID: 216::103

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