Local denial of service via unreclaimed UMEM frames
Published Aug 15, 2026 · Updated Aug 15, 2026
Resource exhaustion in Linux kernel 6.6 allows local users to interrupt service through malformed AF_XDP zero-copy Tx descriptors. The zero-copy Tx batch parser advances its consumer past invalid or oversized multi-buffer fragments without returning their UMEM frames through the completion ring. Exploitation requires an AF_XDP socket, multi-buffer zero-copy operation, and a supporting network device; repeated frame loss exhausts resources and disrupts availability.
Summary
What happened
Resource exhaustion in Linux kernel 6.6 allows local users to interrupt service through malformed AF_XDP zero-copy Tx descriptors. The zero-copy Tx batch parser advances its consumer past invalid or oversized multi-buffer fragments without returning their UMEM frames through the completion ring. Exploitation requires an AF_XDP socket, multi-buffer zero-copy operation, and a supporting network device; repeated frame loss exhausts resources and disrupts availability.
The record
- CVE
- CVE-2026-74558
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-772, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 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=6.6
- Affected versionversion=cf24f5a5feeaae34c1a34d1e04f8ac697290427a <72f2b4516faf55d4dfac2414649d3cffa5fd2c5e
- Affected versionversion=cf24f5a5feeaae34c1a34d1e04f8ac697290427a <e7ce2bad0c33471c8da4dd73dff2119a68f96f3a
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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