CVE-2026-40080

Name	CVE-2026-40080
Description	Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior are vulnerable to Open Redirect through a substring check rather than a host check at str_contains($referer, CACTI_PATH_URL). When the user's login_opts == '1' (redirect to referer after login), the function used $_SERVER['HTTP_REFERER'] directly. An attacker could craft a referer such as https://evil.com/cacti/. Where CACTI_PATH_URL is /cacti/, the substring matches and the user is redirected to evil.com after login. The pre-existing validate_redirect_url() helper at lib/html_utility.php performed proper validation but was not invoked from auth_login_redirect(). This issue has been fixed in version 1.2.31.
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	1140813

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
cacti (PTS)	bullseye	1.2.16+ds1-2+deb11u3	vulnerable
	bullseye (security)	1.2.16+ds1-2+deb11u5	vulnerable
	bookworm, bookworm (security)	1.2.24+ds1-1+deb12u5	vulnerable
	trixie	1.2.30+ds1-1	vulnerable
	forky, sid	1.2.30+ds1-3	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
cacti	source	(unstable)	(unfixed)			1140813

Notes

https://github.com/Cacti/cacti/security/advisories/GHSA-6gr7-53g8-vchq
https://github.com/Cacti/cacti/pull/7039
Fixed by: https://github.com/Cacti/cacti/commit/4c09efaebf3a9faec66969d0b5c4aceaf397f37f (release/1.2.31)