CVE-2026-55369: Waline login accepts a non-string email as a match-all MongoDB query
Waline is a comment system with backend support. Prior to version 1.41.1, the login endpoint POST /api/token reads the email field from the request body without checking its type and passes it straight into the MongoDB storage query. When email is not a string (for example a JSON object such as {"$ne": null}), the MongoDB storage adapter's parseWhere silently DROPS the field rather than rejecting the request, producing an empty filter that matches ALL users. The endpoint then verifies the submitted password against the FIRST user returned (user[0]), which in Waline is the first-registered user — the site administrator. This is a PARTIAL authentication bypass, not a full one. The attacker still needs a valid password for that first user; this is not a zero-knowledge bypass and it does not disclose passwords. Its concrete effects are: (1) the email/identifier factor is removed for the administrator account, (2) user enumeration (a non-string email never fails the "no such user" branch), and (3) credential-stuffing amplification — an attacker can test a leaked or weak password against the administrator account without knowing the administrator's email. This issue has been patched in version 1.41.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Walineto a version that resolves this vulnerability.Fixed in 1.41.1
Event History
Frequently Asked Questions
Which deployments are affected?
Waline deployments using the MongoDB storage adapter are affected when running a version prior to 1.41.1.
What does an attacker need to exploit this issue?
An attacker can send a request to the login endpoint with a non-string email value, but must still know a valid password for the first-registered user, which is the site administrator. The issue does not allow passwordless login or disclose passwords.
What is the practical impact of the missing email check?
It removes the email or identifier factor when testing the administrator's password. This can enable user enumeration and lets attackers test leaked or weak administrator passwords without knowing the administrator email address.
How should this be remediated?
Upgrade Waline to version 1.41.1 or later.