CVE-2026-50635
Severity CVSS v4.0:
HIGH
Type:
CWE-640
Weak Password Recovery Mechanism for Forgotten Password
Publication date:
09/06/2026
Last modified:
23/07/2026
Description
LimeSurvey constructs account password-reset links from the client-supplied HTTP Host header without validating it. The optional allowedHosts allowlist that would constrain this is undefined in the default (and documented) configuration, so LSHttpRequest::checkIsAllowedHost() results in no operation. A remote, unauthenticated attacker who submits a forgotten-password request for a known account (requiring only the target's username and email) with a spoofed Host header causes LimeSurvey to email that account a reset link whose hostname is attacker-controlled while embedding the genuine validation_key. When the recipient or an automated inbound mail-security link scanner dereferences the link, the valid reset token is disclosed to the attacker, who replays it against the legitimate host's newPassword endpoint to set a new password and take over the account.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH
Base Score 3.x
8.80
Severity 3.x
HIGH