Local root escalation via stale io_uring buffer
Published Sep 4, 2025 · Updated Aug 5, 2026
Use-after-free in the Linux kernel allows local users to gain root privileges through io_uring provided-buffer retry handling. The networking path retains a ring-provided buffer across a partial receive retry, leaving req->buf_list stale if the ring is unregistered and allowing shared receives to reuse the same userspace memory. An ordinary unprivileged local account can control the socket timing and unregister the ring, enabling arbitrary kernel reads and writes, root escalation, application-data corruption, or a kernel panic.
Summary
What happened
Use-after-free in the Linux kernel allows local users to gain root privileges through io_uring provided-buffer retry handling. The networking path retains a ring-provided buffer across a partial receive retry, leaving req->buf_list stale if the ring is unregistered and allowing shared receives to reuse the same userspace memory. An ordinary unprivileged local account can control the socket timing and unregister the ring, enabling arbitrary kernel reads and writes, root escalation, application-data corruption, or a kernel panic.
The record
- CVE
- CVE-2025-38730
- Published
- Sep 4, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 4, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.4
- Affected versionversion=c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 <21a4ddb0f5e933f372808c10b9ac704505751bb1
- Affected versionversion=c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 <2eb7937b5fc7fcd90eab7bebb0181214b61b9283
- Affected versionversion=c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 <3b53dc1c641f2884d4750fc25aaf6c36b90db606
- Affected versionversion=c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 <41b70df5b38bc80967d2e0ed55cc3c3896bba781
- Affected versionversion=c56e022c0a27142b7b59ae6bdf45f86bf4b298a1 <fe9da1812f8697a38f7e30991d568ec199e16059
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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