CVE-2026-90439: NGINX ngx_http_v3_module vulnerability
NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpv3module module. When using HTTP/3 with OpenSSL versions <= OpenSSL 3.5.0 under certain configurations, a limited heap buffer overflow could happen while processing a TLS handshake. This can happen in a non-deterministic manner that is beyond the attacker's control. This may cause a heap buffer overflow in the NGINX worker process leading to a restart and/or limited data corruption.
Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or limited data corruption. There is no control plane exposure; this is a data plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed?
NGINX Plus and NGINX Open Source deployments using ngx_http_v3_module with HTTP/3 are affected when they use OpenSSL 3.5.0 or earlier under certain configurations. The issue is limited to the data plane; there is no control plane exposure.
What does an attacker need to do to trigger the issue?
A remote attacker can trigger the condition while NGINX processes a TLS handshake over HTTP/3. The overflow occurs non-deterministically and is beyond the attacker's control.
What is the expected operational impact?
The issue can cause a heap buffer overflow in an NGINX worker process, potentially resulting in a worker restart or limited data corruption. It may be used to cause denial of service on the NGINX system.