Findings

CVE-2026-8711

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_*,…

Published May 19, 2026 · updated Jul 23, 2026 · f5 njs

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.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 19, 2026 · NIST NVD

    Detected

    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 worke

  2. Jul 23, 2026 · NIST NVD

    Updated

    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 worke

Affected

  • cpe f5/njsversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-8711

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-8711

    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 c

    nvd.nist.gov

References

CVE-2026-8711 · ZeroDay Findings