CVE-2026-101025
NGINX ngx_http_js_module vulnerability
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.
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| F5 | NGINX JavaScript | unknown |
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| Vendor | Product | Versions | ||||||||
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| F5 | Nginx Javascript |
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Remediation
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
Advisories
Metrics
Attack Vector Network
Attack Complexity Low
Privileges Required None
Attack Requirements None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact Low
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
Attack Vector Network
Attack Complexity Low
Privileges Required None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact Low
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.316% probability within 30 days)
Exploitation none
Automatable yes
Technical Impact partial
| Link | Providers |
|---|---|
| https://my.f5.com/manage/s/article/K000162614 |
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| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
F5
F5 nginx Javascript |
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| Vendors & Products |
F5
F5 nginx Javascript |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| 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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