CVE-2026-100523 Cotonti through 1.0.0 Open Redirect via message.php redirect parameter
Unauthenticated attackers can redirect users to malicious sites via the message.php redirect parameter, facilitating phishing attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-100523?
CVE-2026-100523 is a medium-severity vulnerability in Cotonti, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-601
Which versions are affected by CVE-2026-100523?
How do I fix CVE-2026-100523?
No fix has been published for CVE-2026-100523 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-100523 being exploited?
There is no known exploitation of CVE-2026-100523 in the wild and no public exploit code.
Sources
Also known as GHSA-g8jm-3grw-8wh2.