Local low-privilege kernel code execution via act_gate use-after-free
Published Mar 18, 2026 · Updated Mar 18, 2026
Use-after-free in affected Linux Kernel releases allows local users to execute kernel code via concurrent act_gate replacement. The act_gate replacement path frees schedule entries while the hrtimer callback or dump path can still traverse them, leaving stale list references. Local users can reach the path from unprivileged user and network namespaces because CAP_NET_ADMIN is checked there; exploitation enables kernel-memory disclosure, arbitrary writes, control-flow hijacking, or a kernel crash.
Summary
What happened
Use-after-free in affected Linux Kernel releases allows local users to execute kernel code via concurrent act_gate replacement. The act_gate replacement path frees schedule entries while the hrtimer callback or dump path can still traverse them, leaving stale list references. Local users can reach the path from unprivileged user and network namespaces because CAP_NET_ADMIN is checked there; exploitation enables kernel-memory disclosure, arbitrary writes, control-flow hijacking, or a kernel crash.
The record
- CVE
- CVE-2026-23245
- Published
- Mar 18, 2026
- Updated
- Mar 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
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=5.8
- Affected versionversion=a51c328df3106663879645680609eb49b3ff6444 <04d75529dc0f9be78786162ebab7424af4644df2
- Affected versionversion=a51c328df3106663879645680609eb49b3ff6444 <58b162e318d0243ad2d7d92456c0873f2494c351
- Affected versionversion=a51c328df3106663879645680609eb49b3ff6444 <62413a9c3cb183afb9bb6e94dd68caf4e4145f4c
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
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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