# CVE-2026-18329: NGINX ngx_http_js_module vulnerability

CVE-2026-18329 is fixed in 4 products on 1 platform, first by DEBIAN-CVE-2026-18329, released September 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-18329
- Priority: High
- CVSS: 8.2 (Moderate)
- EPSS: 0.0065
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 2, 2026
- Weakness: Not Failing Securely ('Failing Open')
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-18329

## Description

Description  NGINX JavaScript (njs) and QuickJS (qjs) engines have a vulnerability when a js_access handler performs asynchronous request body processing and an exception is thrown during asynchronous access-control evaluation before an explicit access denial is returned. An unauthenticated attacker can exploit this vulnerability by sending a crafted HTTP request that triggers an error condition in the access validation logic. This may cause the js_access phase to fail open, allowing the request to proceed instead of being denied, resulting in an authentication or authorization bypass and unauthorized access to protected resources.  Impact  This vulnerability may allow remote attackers to bypass js_access controls. 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libnginx-mod-js Debian 14 | 1.0.1-1 | [DEBIAN-CVE-2026-18329](https://patchblox.com/security/data/fix/linux/debian-cve-2026-18329.md) | Sep 10, 2026 |
| Linux | nginx-mod-njs amzn 2023 | 1.0.1-1.amzn2023.0.1 | [ALAS2023-2026-3095](https://patchblox.com/security/data/fix/linux/alas2023-2026-3095.md) | Sep 28, 2026 |
| Linux | nginx-mod-njs-debuginfo amzn 2023 | 1.0.1-1.amzn2023.0.1 | [ALAS2023-2026-3095](https://patchblox.com/security/data/fix/linux/alas2023-2026-3095.md) | Sep 28, 2026 |
| Linux | nginx-mod-njs-debugsource amzn 2023 | 1.0.1-1.amzn2023.0.1 | [ALAS2023-2026-3095](https://patchblox.com/security/data/fix/linux/alas2023-2026-3095.md) | Sep 28, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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