CVE-2026-101025

Medium

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.

SeverityMedium
CVSS5.3
Exploit probability—
ProductNGINX JavaScript
PublishedOct 14, 2026
First seenOct 14, 2026
Weakness typeCWE-401CWE-401

How to fix

Update
  • F5 NGINX JavaScript1.0.2 or later

Affected products

ProductAffected versionsFixed in
F5 NGINX JavaScript0.7.10 ≤ v < 1.0.21.0.2

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