Cal.comApplication · Cal

CVE-2023-37919

MEDIUM · 5.4 CVSS v3.1 Published 2023-07-25
Fix available
A fix is available. Upgrade to after 3.1.4 or later.
See remediation →
60/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Cal.com is open-source scheduling software. A vulnerability allows active sessions associated with an account to remain active even after enabling 2FA. When activating 2FA on a Cal.com account that is logged in on two or more devices, the account stays logged in on the other device(s) stays logged in without having to verify the account owner's identity. As of time of publication, no known patches or workarounds exist.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

When a user enables two-factor authentication on a Cal.com account that has active sessions on multiple devices, the other device sessions remain authenticated without requiring re-verification through 2FA. This session management flaw allows persisted access from devices that have not completed the 2FA setup process.

MitigationAt time of publication, no vendor patch or workaround exists. Users should manually terminate all other active sessions before enabling 2FA, or administrators should implement additional session management controls at the infrastructure level.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Cal.comApplication
Affected:<= 3.1.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine Cal.com installation version
    Check the installed version by inspecting package.json in the application root, the Docker image tag, or the /api/version endpoint if available
    Affected if the installed version is 3.1.4 or any version lower than 3.1.4
  2. Verify 2FA is enabled on an account
    Access the user security settings in the Cal.com UI under Profile > Security, or query the database users table for the twoFactorEnabled flag
    Affected if two-factor authentication is turned on for any user account
  3. Identify active user sessions
    Query the sessions table in the database or access the session management interface in the admin panel to list active sessions per user
    Affected if multiple concurrent sessions exist for a user who has enabled 2FA
  4. Confirm session invalidation behavior
    After enabling 2FA, attempt to use a pre-existing session token from another device to access the API or web interface without triggering 2FA verification
    Affected if the older session remains valid and allows access without completing 2FA challenge

You are affected if you are running Cal.com version 3.1.4 or lower, have 2FA enabled on any account, and that account has or had multiple device sessions - the older sessions remain authenticated without 2FA re-verification.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 3.1.4
Interim mitigation

At time of publication, no vendor patch or workaround exists. Users should manually terminate all other active sessions before enabling 2FA, or administrators should implement additional session management controls at the infrastructure level.

Fix this in Cal.com Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-37919 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-37919 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data