Vulnerability in F5 nginx JavaScript
CVE-2026-101025
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- my.f5.com/manage/s/article/K000162614 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-101025?
- CVE-2026-101025 is a medium-severity vulnerability in F5 nginx JavaScript, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.3/10. Published 2026-10-14.
- How severe is CVE-2026-101025?
- Medium severity. CVSS v3 base score is 5.3 out of 10.