Heap-based buffer overflow in NGINX Open Source and NGINX Plus - CVE-2026-90439
Published: September 15, 2026
Vulnerability identifier: #VU150109
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90439
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service or limited data corruption.
The vulnerability exists due to a heap-based buffer overflow in the ngx_http_v3_module module when processing a TLS handshake over HTTP/3. A remote attacker can initiate a TLS handshake to cause a denial of service or limited data corruption.
The issue occurs non-deterministically and is beyond the attacker\'s control. Only configurations using HTTP/3 with OpenSSL 3.5.0 or earlier are affected.
Affected software
NGINX Open Source
NGINX Plus
NGINX Plus
How to mitigate CVE-2026-90439
Install security update from vendor's website.
NGINX Open Source - addressed in versions 1.30.5, 1.31.6
NGINX Plus - addressed in versions 37.0.6.1, 37.1.1.1
NGINX Plus - addressed in versions 37.0.6.1, 37.1.1.1