CVE-2026-18329

HIGHCVSS 8.2/10EPSS 0.38%

Last modified

CVE-2026-18329 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
F5NGINX JavaScript>= 1.0.0, < 1.0.1; >= 0.9.9, < *

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-18329?
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.
How severe is CVE-2026-18329?
CVE-2026-18329 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2026-18329?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-18329?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST