CVE-2026-8711

Published: May 19, 2026Modified: Jun 4, 2026

9.2

Vector

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

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:XShow less

Source: f5sirt@f5.com (Secondary)

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.

Affected (1)

Products: F5: Njs

1 product

Njs

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
F5 Njs	From 0.9.4 to 0.9.9

Related CWEs

CWE-122

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

References (1)

https://my.f5.com/manage/s/article/K000161307

Source: f5sirt@f5.com

Vendor Advisory

Timeline

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