CVE-2026-9256
published 2026-05-22CVE-2026-9256: NGINX ngx_http_rewrite_module vulnerability NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability…
high8.1CVSS 3.1
AVNACHPRNUINSUCHIHAH
NGINX ngx_http_rewrite_module vulnerability
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when a rewrite directive uses a regex pattern with distinct, overlapping Perl-Compatible Regular Expression (PCRE) captures (for example, ^/((.*))$) and a replacement string that references multiple such captures (for example, $1$2) in a redirect or arguments context. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| f5 | nginx_open_source | >= 0.1.17 < * | * |
| f5 | nginx_open_source | >= 1.30.0 < 1.30.2 | 1.30.2 |
| f5 | nginx_open_source | >= 1.31.0 < 1.31.1 | 1.31.1 |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | >= 37.0 < 37.0.1.1 | 37.0.1.1 |
| f5 | nginx_plus | >= R32 < R32 P7 | R32 P7 |
| f5 | nginx_plus | >= R36 < R36 P5 | R36 P5 |
| insights-proxy | insights-proxy-container-rhel9 | — | — |
| nginx_1.24 | nginx | — | — |
| nginx_1.26 | nginx | — | — |
| ubuntu | nginx | — | — |