Vulnerability in F5 NGINX JavaScript

[ Description ]Official description

Description NGINX JavaScript (njs) has a vulnerability where the built-in njs engine leaks a libxml2 parser context when xml.parse() fails. The failure path did not register cleanup and the context was not released for the lifetime of the process. An unauthenticated attacker may send requests with malformed XML and can cause unbounded memory growth in long-lived NGINX worker processes. Impact This vulnerability may allow remote attackers to send requests that trigger repeated parsing of malformed XML and may lead to NGINX worker termination or denial of service. There is no control plane exposure; this is a data plane issue only.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• CERT-FR19 Oct 2026CERTFR-2026-AVI-1341

  Multiple vulnerabilities in F5 products Translated from French

  Multiple vulnerabilities have been discovered in F5 products. Some of them allow an attacker to cause remote arbitrary code execution, remote denial of service and a breach of data confidentiality.

  CVE-2026-91184CVE-2026-101019CVE-2026-96615+8 more CVEs
• BSI CERT-Bund14 Oct 2026WID-SEC-2026-3948

  NGINX: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-101025CVE-2026-15176CVE-2026-91184+8 more CVEs

[ References ]References

• my.f5.com/manage/s/article/K000162614