CVE-2026-8711 Details
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.
A heap buffer overflow vulnerability has been identified in NGINX JavaScript (njs) versions 0.9.4 through 0.9.8, within the ngx_http_js_module. The vulnerability arises when the js_fetch_proxy directive is set with at least one client-controlled NGINX variable, such as $http_*, $arg_*, or $cookie_*, and a location that calls the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this by sending crafted HTTP requests, causing a heap buffer overflow in the NGINX worker process, which leads to a restart. Furthermore, on systems with Address Space Layout Randomization (ASLR) disabled, this vulnerability could be exploited for code execution.
Users can upgrade to NGINX JavaScript version 0.9.9 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 19, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://my.f5.com/manage/s/article/K000161307 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-122 | Heap-based Buffer Overflow | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| f5 njs | >= 0.9.4, < 0.9.9 |
CPE
Remediation
| |
Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 4, 2026 | Initial Analysis | [email protected] |
| May 21, 2026 | CVE Modified | [email protected] |
| May 19, 2026 | New CVE Received | [email protected] |