Cacti: Open Redirect via HTTP_REFERER substring check in auth_login_redirect

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.

Scores

EPSS (exploitation in 30 days)

0.26% · top 83% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: poc · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.1.

Weakness

• CWE-601: URL Redirection to Untrusted Site ('Open Redirect') (opens in a new tab)All about CWE-601 and its CVEs

Affected products

• Cacti · cacti

  • affected < 1.2.31

References (2)

• https://github.com/Cacti/cacti/security/advisories/GHSA-6gr7-53g8-vchq (opens in a new tab)x_refsource_CONFIRMexploit
• https://github.com/Cacti/cacti/releases/tag/release%2F1.2.31 (opens in a new tab)x_refsource_MISC

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-40080](https://trackcve.app/badge/CVE-2026-40080.svg)](https://trackcve.app/cve/CVE-2026-40080)

Record last updated 26 Jun 2026, 14:09 UTC.