CVE-2026-101025
NGINX ngx_http_js_module vulnerability
- Published
- Updated
- Reserved
- Assigned by
- f5
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| f5CNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| f5CNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Awaiting Analysis | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.32% · top 75% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Weakness
Affected products
- affected 0.7.10 – < 1.0.2
What to do
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.
References (1)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-101025)Record last updated .