CVE-2026-42946 PUBLISHED

NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability

Assigner: f5
Reserved: 30.04.2026 Published: 13.05.2026 Updated: 13.05.2026

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.

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
CVSS Score: 6.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	Low

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS Score: 8.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	Low	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	F5
Product	NGINX Plus
Versions	Default: unknown unaffected from R37 to * (excl.) affected from R36 to R36 P4 (excl.) affected from R32 to R32 P6 (excl.)

Vendor	F5
Product	NGINX Open Source
Versions	Default: unaffected unaffected from 1.31.0 to * (excl.) affected from 0.8.42 to 1.30.1 (excl.)

Credits

F5 acknowledges Zhenpeng (Leo) Lin of depthfirst for bringing this issue to our attention and following the highest standards of coordinated disclosure. finder

References

https://my.f5.com/manage/s/article/K000161027

Problem Types

CWE-789: Memory Allocation with Excessive Size Value CWE
CWE-823: Use of Out-of-range Pointer Offset CWE