Socket memory-limit bypass via reversed clamping
Published May 28, 2026 · Updated May 28, 2026
Buffer-size validation in affected Linux Kernel branches starting with 5.5 allows local users to exceed configured vsock memory limits. vsock_update_buffer_size() clamps the requested size to buffer_max_size before enforcing buffer_min_size, so a minimum above the maximum overwrites the upper bound. A local low-privileged user must configure a minimum above the maximum; the resulting vsk->buffer_size violates the intended socket memory boundary.
Summary
What happened
Buffer-size validation in affected Linux Kernel branches starting with 5.5 allows local users to exceed configured vsock memory limits. vsock_update_buffer_size() clamps the requested size to buffer_max_size before enforcing buffer_min_size, so a minimum above the maximum overwrites the upper bound. A local low-privileged user must configure a minimum above the maximum; the resulting vsk->buffer_size violates the intended socket memory boundary.
The record
- CVE
- CVE-2026-46234
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-787, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 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=5.5
- Affected versionversion=b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 <0b68881501460c3761f196469e1e503218c5e536
- Affected versionversion=b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 <2602f7bb5818e92315feeaeb71d8ce4d5c9ab160
- Affected versionversion=b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 <310da27932dd0afe7ce7456dfe1f0814c3301f41
- Affected versionversion=b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 <a998a7e250bf976539e05a00ec64a81292afecaa
- Affected versionversion=b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 <d114bfdc9b76bf93b881e195b7ec957c14227bab
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.
Weakness, pattern, technique
Public exploit references
- vsock buffer-size clamping reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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