Linux Kernel up to 6.18.48/7.1.10/7.2.0 io_uring io_req_local_work_add/io_eventfd_signal work_list/in_eventfd race condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$0-$5k0.00+

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.18.48/7.1.10/7.2.0. The impacted element is the function io_req_local_work_add/io_eventfd_signal of the component io_uring. The manipulation of the argument work_list/in_eventfd results in race condition. This vulnerability is identified as CVE-2026-80920. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.18.48/7.1.10/7.2.0. Affected is the function io_req_local_work_add/io_eventfd_signal of the component io_uring. The manipulation of the argument work_list/in_eventfd with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: io_uring: defer eventfd signaling when queued from a wakeup handler io_req_local_work_add() signals the CQ ring eventfd inline when it is the one to push the first entry onto ->work_list. For DEFER_TASKRUN rings that add is frequently done from a waitqueue wakeup handler, where an arbitrary waitqueue lock is held. eventfd_signal_mask() only refuses to recurse when current->in_eventfd is set, but that bit is set by eventfd_signal_mask() itself. If the wake chain starts somewhere else, signal goes out inline and can feed back into epoll. Add IOU_F_TWQ_IN_WAKE, set it on the task_work add done from the three waitqueue callbacks, and use it to force io_eventfd_signal() down the existing call_rcu_hurry() deferral instead of signaling inline.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-80920 since 08/26/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/09/2026).

Upgrading to version 6.18.49, 7.1.11, 7.2.1 or 7.3-rc1 eliminates this vulnerability. Applying the patch e22f4494cc9487d326e5e3067f33dea7c1e442b2/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit 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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
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: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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 6.18.49/7.1.11/7.2.1/7.3-rc1
Patch: e22f4494cc9487d326e5e3067f33dea7c1e442b2/b6bb334b0e9348887e3e55e1f494b0c3b8fbf59f/40b6ccf68731809ceb85c6e9f0f8f2ed61c7aa5a/cd305ee3633a45fcf5f3a5d83f99f3cb77d87b6e

Timelineinfo

08/26/2026 CVE reserved
09/09/2026 +14 days Advisory disclosed
09/09/2026 +0 days VulDB entry created
09/09/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80920 (🔒)
GCVE (CVE): GCVE-0-2026-80920
GCVE (VulDB): GCVE-100-401826

Entryinfo

Created: 09/09/2026 18:32
Changes: 09/09/2026 18:32 (60)
Complete: 🔍
Cache ID: 216::103

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