{"id":"DEBIAN-CVE-2026-9256","details":"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.","modified":"2026-09-01T16:07:07.434229437Z","published":"2026-05-22T15:16:27.073Z","upstream":["CVE-2026-9256"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-9256"}],"affected":[{"package":{"name":"nginx","ecosystem":"Debian:12","purl":"pkg:deb/debian/nginx?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.22.1-9+deb12u8"}]}],"versions":["1.22.1-9","1.22.1-9+deb12u1","1.22.1-9+deb12u2","1.22.1-9+deb12u3","1.22.1-9+deb12u4","1.22.1-9+deb12u5","1.22.1-9+deb12u6","1.22.1-9+deb12u7"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-9256.json"}},{"package":{"name":"nginx","ecosystem":"Debian:13","purl":"pkg:deb/debian/nginx?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.26.3-3+deb13u6"}]}],"versions":["1.26.3-3","1.26.3-3+deb13u1","1.26.3-3+deb13u2","1.26.3-3+deb13u3","1.26.3-3+deb13u4","1.26.3-3+deb13u5"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-9256.json"}},{"package":{"name":"nginx","ecosystem":"Debian:14","purl":"pkg:deb/debian/nginx?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.30.1-3"}]}],"versions":["1.26.3-3","1.28.0-1","1.28.0-2","1.28.0-3","1.28.0-4","1.28.0-5","1.28.0-6","1.28.1-1","1.28.1-2","1.28.1-3","1.28.2-1","1.28.2-2","1.28.2-3","1.28.2-4","1.28.3-1","1.28.3-2","1.30.0-1","1.30.0-2","1.30.0-3","1.30.0-4","1.30.1-1","1.30.1-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-9256.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}