Vulnerability Report

CVE-2026-40080

Title: Cacti Open Redirect via substring check in HTTP_REFERER

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-40080.

CWE Category CWE-601
Published Date Jun 25, 2026
Modified Date Jun 29, 2026
Exploit Status Not Found
Score 6.1 CVSS v3.1
Exploit Probability (EPSS)
0.19%

Vulnerability Summary

CVE-2026-40080: 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.

Impacted Vendors

T
the_cacti_group 1
C
cacti 1

Reference Links

https://github.com/Cacti/cacti/releases/tag/release%2F1.2.31 https://github.com/Cacti/cacti/security/advisories/GHSA-6gr7-53g8-vchq
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.1
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-40080 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected Stack

No specific products linked.