Vulnerability · Published Sep 26, 2026 · Assigned by VulnCheck
CVE-2026-100523Cotonti through 1.0.0 Open Redirect via message.php redirect parameter
Medium 6.1
In plain English
A medium-severity open redirect in Cotonti from Cotonti. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.2%top 91.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Cotonti through 1.0.0 contains an open redirect vulnerability in message.php that base64-decodes the redirect parameter without domain validation. Unauthenticated attackers can craft malicious links with encoded external URLs to redirect users to arbitrary sites via meta refresh tags for phishing attacks.
Affected products (as reported)
Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
References
- https://github.com/Cotonti/Cotonti/issues/1907 issue-tracking
- https://github.com/Cotonti/Cotonti/pull/1908 issue-tracking, patch
- https://github.com/Cotonti/Cotonti/blob/1.0.0/message.php technical-description
- https://github.com/Cotonti/Cotonti/blob/1.0.0/system/common.php technical-description
- https://github.com/Cotonti/Cotonti product
- VulnCheck Advisory: Cotonti through 1.0.0 Open Redirect via message.php redirect parameter third-party-advisory