NGINX
CVE-2026-42945: NGINX ngx_http_rewrite_module vulnerability
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| NGINX Plus R37 | Not affected |
| NGINX Plus R36 | R36 P4 or later |
| NGINX Plus R32 | R32 P6 or later |
| NGINX Open Source 1.31 | Not affected |
| NGINX Open Source 0.6 | 1.30.1 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its 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.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.