# CVE-2026-40080 — cacti

> As of 2026-06-26, CVE-2026-40080 is a MEDIUM-severity vulnerability in cacti, CVSS v3.1 6.1, EPSS 0.1% (4.2th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-40080 as of 2026-06-26; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-06-26

## What is 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.

The record classifies CVE-2026-40080 under weakness class [CWE-601](https://intel.threadlinqs.com/cwe/CWE-601). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 102 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.1 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 4.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-06-25, last modified 2026-06-26

## Is CVE-2026-40080 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Cacti](https://intel.threadlinqs.com/vendors/cacti): cacti

## How to fix CVE-2026-40080

No vendor patch reference has been recorded for CVE-2026-40080 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-40080

No threat campaign in the Threadlinqs corpus currently references CVE-2026-40080, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-06-28. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/Cacti/cacti/security/advisories/GHSA-6gr7-53g8-vchq)

**Other references**

- [github.com](https://github.com/Cacti/cacti/releases/tag/release%2F1.2.31)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-40080
Full detection coverage and IOCs for threats exploiting CVE-2026-40080 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp