CVE-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) 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.
- CVSS 4.0
- 9.2
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS
- 68% chance of exploitation in the next 30 days; higher than 99% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-122, CWE-131
- Published
- Modified
- Record from
- the NVD, synced
Affected
- f5:dos
- f5:nginx_gateway_fabric
- f5:nginx_ingress_controller
- f5:nginx_instance_manager
- f5:nginx_open_source
- f5:nginx_plus
- f5:waf