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CVE PROGRAM SOURCE RECORD9.2 Critical

CVE-2026-9256

NGINX ngx_http_rewrite_module vulnerability

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Status
Published
Published
Updated
Assigning organization
f5

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

F5 NGINX Plus

Default version status: unknown

  • 37.0 to < 37.0.1.1affected
  • R36 to < R36 P5affected
  • R32 to < R32 P7affected

F5 NGINX Open Source

Default version status: unaffected

  • 1.31.0 to < 1.31.1affected
  • 1.30.0 to < 1.30.2affected
  • 0.1.17 to ≤ 0.9.7affected

References