cvedb.io
CVE-2026-9256
HIGH · CVSS 8.1
EPSS exploitation probability: 0%
Published 2026-05-22T15:16:27.073 · Last modified 2026-06-30T03:21:46.640

Summary

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 reac

Affected products

f5 — nginx_open_source

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.