Application crash via unchecked XCB extension reply
Published Mar 27, 2024 · Updated Nov 4, 2025
NULL pointer dereference in Mesa 23.0.4 allows attackers to crash an X11 software-rendering application via a failed MIT-SHM query. In the reported has_error path, check_xshm reads shm_reply->major_opcode after xcb_query_extension_reply without checking whether the reply pointer is NULL. Reachability requires the GLX software-rendering path to query MIT-SHM against an errored X connection; upstream disputes any demonstrable security scenario, bounding the reported effect to an application crash.
Summary
What happened
NULL pointer dereference in Mesa 23.0.4 allows attackers to crash an X11 software-rendering application via a failed MIT-SHM query. In the reported has_error path, check_xshm reads shm_reply->major_opcode after xcb_query_extension_reply without checking whether the reply pointer is NULL. Reachability requires the GLX software-rendering path to query MIT-SHM against an errored X connection; upstream disputes any demonstrable security scenario, bounding the reported effect to an application crash.
The record
- CVE
- CVE-2023-45931
- Published
- Mar 27, 2024
- Updated
- Nov 4, 2025
- Vendor
- Mesa
- Product
- Mesa
- Classifications
- CWE-476, T1499
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Mar 27, 2024CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=23.0.4
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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