--- cve: "CVE-2026-9256" severity: "CRITICAL" cvss: 9.2 epss: "10%" vendor: "F5" kev: false exploited: false published: "2026-05-22 15:16:27" tags: [cve, security, critical] source: tsecurity.de CVE-Dossier exported: "2026-09-05T23:17:55+02:00" --- # CVE-2026-9256 > 9.2 CRITICAL ## Beschreibung 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. ## CVSS-Vektor ``` 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 ``` | Metrik | Wert | Bewertung | |---|---|---| | AV Angriffsvektor | Netzwerk | bad | | AC Komplexität | Hoch | good | | PR Privilegien | Keine | bad | | UI Interaktion | Keine | bad | ## Patch verfügbar (OSV) - a92a537860c7b87d3793d9eb41c9cf3ed833b53c (Commit) - dda57a2d256e8e1aa425c7ae715c2861e2e4b239 (Commit) ## Referenzen - - - - - - - - - - - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-9256) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_