Vulnerability · Published May 13, 2026 · Assigned by f5

CVE-2026-42946NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability

Medium 6.5

In plain English

A medium-severity security flaw in NGINX Open Source from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.9%top 39.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A vulnerability exists in the ngx_http_scgi_module and ngx_http_uwsgi_module modules that may result in excessive memory allocation or an over-read of data. When scgi_pass or uwsgi_pass is configured, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to read the memory of the NGINX worker process or restart it. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.21	nginx	1.26.3-r1	ALPINE-CVE-2026-42946
Alpine:v3.22	nginx	1.28.3-r1	ALPINE-CVE-2026-42946
Alpine:v3.23	nginx	1.28.3-r1	ALPINE-CVE-2026-42946
Alpine:v3.24	nginx	1.30.1-r0	ALPINE-CVE-2026-42946
Debian:12	nginx	1.22.1-9+deb12u8	DEBIAN-CVE-2026-42946
Debian:13	nginx	1.26.3-3+deb13u6	DEBIAN-CVE-2026-42946
Debian:14	nginx	1.30.0-4	DEBIAN-CVE-2026-42946
Ubuntu:22.04:LTS	nginx	1.18.0-6ubuntu14.12	UBUNTU-CVE-2026-42946
Ubuntu:24.04:LTS	nginx	1.24.0-2ubuntu7.9	UBUNTU-CVE-2026-42946
Ubuntu:25.10	nginx	1.28.0-6ubuntu1.4	UBUNTU-CVE-2026-42946
Ubuntu:26.04:LTS	nginx	1.28.3-2ubuntu1.2	UBUNTU-CVE-2026-42946

Affected products (as reported)

Vendor	Product	Versions
F5	NGINX Plus	R36 – before R36 P4R32 – before R32 P6
F5	NGINX Open Source	0.8.42 – before 1.30.1

Weakness: CWE-789, CWE-823 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L

References

https://my.f5.com/manage/s/article/K000161027 vendor-advisory, patch