Worker termination via MP4 atom count overflow
Published Mar 24, 2026 · Updated Mar 24, 2026
Integer overflow in F5 NGINX Open Source 1.1.19 through 1.28.2 and 1.29.0 through 1.29.6 allows local users to terminate a worker. On 32-bit builds, MP4 atom-entry count validation overflows, so an invalid atom is accepted and accessed beyond the allocated MP4 buffer. The module must be built in, the mp4 directive must enable processing, and the user must make NGINX process a crafted MP4 file.
Summary
What happened
Integer overflow in F5 NGINX Open Source 1.1.19 through 1.28.2 and 1.29.0 through 1.29.6 allows local users to terminate a worker. On 32-bit builds, MP4 atom-entry count validation overflows, so an invalid atom is accepted and accessed beyond the allocated MP4 buffer. The module must be built in, the mp4 directive must enable processing, and the user must make NGINX process a crafted MP4 file.
The record
- CVE
- CVE-2026-27784
- Published
- Mar 24, 2026
- Updated
- Mar 24, 2026
- Vendor
- F5 Networks
- Product
- NGINX Open Source
- Classifications
- CWE-190, T1499.004
- 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.1.19 <1.28.3
- Affected versionversion=1.29.0 <1.29.7
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
- nGixshell CVE scanner and exploit frameworkproof of concept · unverified
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Technologies
Your stack
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Your stack
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