CVE-2026-1642

Name	CVE-2026-1642
Description	A vulnerability exists in NGINX OSS and NGINX Plus when configured to proxy to upstream Transport Layer Security (TLS) servers. An attacker with a man-in-the-middle (MITM) position on the upstream server side—along with conditions beyond the attacker's control—may be able to inject plain text data into the response from an upstream proxied server. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1127053

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
nginx (PTS)	bullseye	1.18.0-6.1+deb11u3	vulnerable
	bullseye (security)	1.18.0-6.1+deb11u5	vulnerable
	bookworm	1.22.1-9+deb12u3	vulnerable
	trixie	1.26.3-3+deb13u1	vulnerable
	forky, sid	1.28.1-2	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
nginx	source	(unstable)	(unfixed)			1127053

Notes

https://www.openwall.com/lists/oss-security/2026/02/05/1
https://my.f5.com/manage/s/article/K000159824
Fixed by: https://github.com/nginx/nginx/commit/784fa05025cb8cd0c770f99bc79d2794b9f85b6e (release-1.28.2)