MEDIUM · 6.8

CVE-2026-85238

MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authentica...

Vulnerability Description

MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing session without first rotating the session identifier. As a result, if an attacker can cause a victim to use a session identifier known to the attacker before authentication, that same session identifier remains valid after the victim successfully authenticates. The attacker could subsequently reuse the fixed session identifier to access the victim's authenticated MISP session, potentially gaining the privileges associated with the victim's account. The issue occurs because __customAuthentication() wrote the authenticated user into the existing CakePHP session while the call to Session->renew() had previously been disabled. The patch restores session identifier rotation when a new authentication occurs or when the authenticated user changes, while avoiding unnecessary session renewal on every request.

CVSS Score

6.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE

Affected Products

VendorProductVersions
Misp-ProjectMisp<= 2.5.45

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-85238?

CVE-2026-85238 is a vulnerability with a CVSS score of 6.8 (MEDIUM). MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authentica...

How severe is CVE-2026-85238?

CVE-2026-85238 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-85238?

Check the references section above for vendor advisories and patch information. Affected products include: Misp-Project Misp.