Worker restart via TLS handshake heap overflow
Published Sep 15, 2026 · Updated Sep 15, 2026
Heap buffer overflow in F5 Networks NGINX Open Source and NGINX Plus allows remote attackers to restart workers via a TLS handshake. With HTTP/3 enabled and OpenSSL 3.5.0 or earlier, TLS handshake processing non-deterministically overruns a limited heap buffer in ngx_http_v3_module. The trigger depends on configurations and timing beyond attacker control; exposure is data-plane only and results in a worker restart or limited data corruption.
Summary
What happened
Heap buffer overflow in F5 Networks NGINX Open Source and NGINX Plus allows remote attackers to restart workers via a TLS handshake. With HTTP/3 enabled and OpenSSL 3.5.0 or earlier, TLS handshake processing non-deterministically overruns a limited heap buffer in ngx_http_v3_module. The trigger depends on configurations and timing beyond attacker control; exposure is data-plane only and results in a worker restart or limited data corruption.
The record
- CVE
- CVE-2026-90439
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- F5 Networks
- Product
- NGINX Open Source
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 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=1.29.2 <1.31.6
- Affected versionversion=1.30.4 <1.30.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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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