Local use-after-free via perf mmap race
Published Mar 18, 2026 · Updated Mar 18, 2026
Use-after-free in Linux Kernel 6.14 through 6.18.16 and 6.19 through 6.19.6 allows local users to trigger unsafe ring-buffer access. perf_mmap releases mmap_mutex around map_range(), letting a concurrent dependent-event mapping acquire a ring-buffer reference after failed setup has reduced its refcount to zero. A low-privileged local user must race a failing perf mmap setup with another mapping; the stale reference can cause a kernel use-after-free or refcount saturation.
Summary
What happened
Use-after-free in Linux Kernel 6.14 through 6.18.16 and 6.19 through 6.19.6 allows local users to trigger unsafe ring-buffer access. perf_mmap releases mmap_mutex around map_range(), letting a concurrent dependent-event mapping acquire a ring-buffer reference after failed setup has reduced its refcount to zero. A low-privileged local user must race a failing perf mmap setup with another mapping; the stale reference can cause a kernel use-after-free or refcount saturation.
The record
- CVE
- CVE-2026-23248
- Published
- Mar 18, 2026
- Updated
- Mar 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Mar 18, 2026CVE publishedPublication date reported by the CVE source.
- Mar 18, 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=6.14
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <77de62ad3de3967818c3dbe656b7336ebee461d2
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <ac7ecb65af170a7fc193e7bd8be15dac84ec6a56
- Affected versionversion=b709eb872e19a19607bbb6d2975bc264d59735cf <c27dea9f50ed525facb62ef647dddc4722456e07
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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