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.
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| F5 | NGINX JavaScript | unknown |
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Vendor Workaround
Use the QuickJS engine with js_engine qjs;, which is not affected. Where migration is not possible, avoid passing attacker-controlled XML to xml.parse(), reject or rate-limit malformed input, and use worker memory limits.
Tracking
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No advisories yet.
| Link | Providers |
|---|---|
| https://my.f5.com/manage/s/article/K000162614 |
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Wed, 14 Oct 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | NGINX ngx_http_js_module vulnerability | |
| Weaknesses | CWE-401 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: f5
Published:
Updated: 2026-10-14T14:40:29.324Z
Reserved: 2026-09-30T21:56:14.628Z
Link: CVE-2026-101025
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-10-14T15:17:01.880
Modified: 2026-10-14T16:04:11.750
Link: CVE-2026-101025
Redhat
No data.
OpenCVE Enrichment
No data.
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CWE-401
Missing Release of Memory after Effective Lifetime