Kernel compromise via double-reused anonymous VMA
Published Mar 24, 2026 · Updated Mar 24, 2026
Use-after-free in the rmap memory manager in No-Chicken Echo-Mate before V250329 allows local users to trigger dangling kernel pointer dereferences. In mm/rmap.c, anon_vma_clone() uses the combined anon_vma->degree counter to decide reuse, allowing one anon_vma to remain attached to two VMAs; later VMA merging leaves dangling page->mapping pointers that rmap walks dereference. A low-privilege local account and complex VM mappings are required; no user interaction is needed, and successful exploitation can compromise the kernel.
Summary
What happened
Use-after-free in the rmap memory manager in No-Chicken Echo-Mate before V250329 allows local users to trigger dangling kernel pointer dereferences. In mm/rmap.c, anon_vma_clone() uses the combined anon_vma->degree counter to decide reuse, allowing one anon_vma to remain attached to two VMAs; later VMA merging leaves dangling page->mapping pointers that rmap walks dereference. A low-privilege local account and complex VM mappings are required; no user interaction is needed, and successful exploitation can compromise the kernel.
The record
- CVE
- CVE-2026-4737
- Published
- Mar 24, 2026
- Updated
- Mar 24, 2026
- Vendor
- No-Chicken
- Product
- Echo-Mate
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 24, 2026CVE publishedPublication date reported by the CVE source.
- Mar 24, 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?
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- Affected versionversion=0 <V250329
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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