VULNERABILITY INTELLIGENCE
CVE-2026-8711
CVSS score9.2 CRITICAL
EPSS probability9.69%
CISA KEVNot currently listed
Published2026-05-19
Last modified2026-07-23
CVSS vectorCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Description
NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker 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.
Weakness classification
- CWE-122: Heap-based Buffer Overflow
Primary references
- f5sirt@f5.com — Vendor Advisory