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CVE search · CVE-2026-9256

CVE-2026-9256

critical 9.2

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.

Open in the NVD CVE.org JSON

Details

Status
Modified
Published
Last changed
Source
f5sirt@f5.com
Weakness
CWE-122

Severity

VersionScoreVectorSource
CVSS 4.0 critical 9.2 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 f5sirt@f5.comSecondary
CVSS 3.1 high 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H f5sirt@f5.comSecondary
CVSS 3.1 high 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H 0b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary

Affected products

Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.

  • f5 · nginx_open_source
  • f5 · nginx_plus
  • f5 · dos
  • f5 · nginx_gateway_fabric
  • f5 · nginx_ingress_controller
  • f5 · nginx_instance_manager
  • f5 · waf
  • redhat · discovery
  • redhat · hardened_images
  • redhat · update_infrastructure
  • debian · debian_linux
  • redhat · enterprise_linux

References