CVE-2026-100523
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.1 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-601
- Record status
- Deferred
Attack profile CVSS 4.0 · 5.1
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- None
- Privileges needed
- None
- User interaction
- Active
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-100523.md and follow it. Check whether this project is affected by CVE-2026-100523. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
References
- https://github.com/Cotonti/Cotonti
- https://github.com/Cotonti/Cotonti/blob/1.0.0/message.php
- https://github.com/Cotonti/Cotonti/blob/1.0.0/system/common.php
- https://github.com/Cotonti/Cotonti/issues/1907
- https://github.com/Cotonti/Cotonti/pull/1908
- https://www.vulncheck.com/advisories/cotonti-through-1.0.0-open-redirect-via-message-php-redirect-parameter