CVE-2026-78222

NGINX ngx_http_js_module vulnerability

Published Sep 2, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
A vulnerability exists in NGINX JavaScript where a malformed HTTP response received by ngx.fetch() can crash an NGINX worker when trusted JavaScript reads Response.statusText. Exploitation requires control or influence over the fetched HTTP response.

Impact:
This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system. 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.

Remediation

Vendor Workaround

Restrict ngx.fetch() destinations to trusted servers and avoid reading Response.statusText for responses from attacker-controlled or attacker-influenced endpoints. Using HTTPS with certificate verification reduces exposure to network-based response manipulation but does not protect against a malicious or compromised fetched server

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared F5
F5 nginx Javascript
Vendors & Products F5
F5 nginx Javascript
Type Values Removed Values Added
Description A vulnerability exists in NGINX JavaScript where a malformed HTTP response received by ngx.fetch() can crash an NGINX worker when trusted JavaScript reads Response.statusText. Exploitation requires control or influence over the fetched HTTP response. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system. 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-476
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
f5
Published
Updated
Sep 2, 2026, 5:59 PM
Reserved
Aug 25, 2026, 11:21 PM
Status
Awaiting Analysis
Published
Sep 2, 2026, 4:17 PM
Modified
Sep 2, 2026, 7:23 PM