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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| F5 | NGINX JavaScript | 1.0.0 – < 1.0.1, 0.9.9 | 1.0.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libnginx-mod-js | 1.0.1-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libnginx-mod-js | No fix yet | — |
| Ubuntu 24.04 LTS | libnginx-mod-js | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | libnginx-mod-js | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | nginx-mod-njs | 1.0.1-1.amzn2023.0.1 | ALAS2023-2026-3095 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | nginx | 1.30.4-1 | — |
Advisories 1
- ALAS2023-2026-3095 Important: nginx-mod-njs security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
References
- https://my.f5.com/manage/s/article/K000162599 vendor-advisory