CVE-2026-42945
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module.
Published May 13, 2026 · updated Sep 10, 2026 · f5 dos
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.
Code
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No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 13, 2026 · NIST NVD
Detected
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 it
Sep 10, 2026 · NIST NVD
Updated
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 it
Affected
- cpe f5/dosversion unspecified
- cpe f5/dos4.8.0
- cpe f5/nginx gateway fabricversion unspecified
- cpe f5/nginx ingress controllerversion unspecified
- cpe f5/nginx instance managerversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2026-42945
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-42945
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)
nvd.nist.gov