23 Oct 2026 15:48:27 UTC
NGINX ngx_http_rewrite_module vulnerability
cve-program · CVE-2026-42945 · Published
CVE-2026-42945
NGINX ngx_http_rewrite_module vulnerability
CVSS 3.1 8.1 HIGHCVSS 4.0 9.2 CRITICALCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-42945
PublishedNGINX 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.
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