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Heap-based Buffer Overflow The advisory has been revoked - it doesn't affect any version of package nginx-mod-stream  (opens in a new tab)

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EPSS
9.96% (96th percentile)

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  • Snyk IDSNYK-RHEL10-NGINXMODSTREAM-16874742
  • published26 May 2026
  • disclosed22 May 2026
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Introduced: 22 May 2026

CVE-2026-9256  (opens in a new tab)
CWE-122  (opens in a new tab)

Amendment

The Red Hat security team deemed this advisory irrelevant for RHEL:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx-mod-stream package and not the nginx-mod-stream package as distributed by RHEL.

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.