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Improper AuthenticationWeakness · CWE-287

CVE-2026-55666

CRITICAL · 9.3 CVSS v4.0 Published 2026-06-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 8 weeks old

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
Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, in apps/meteor/app/apple/server/loginHandler.ts, handleIdentityToken parses a JWT issued by Apple during the OAuth flow. The try block checks for an email parameter. If the JWT does not contain an email address, the application falls back to accepting an arbitrary email value supplied directly in the request. Attackers are able to forge Apple JWTs that do not contain an email address and leverage this vulnerability to carry out account takeover attacks. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.

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

Rocket.Chat's Apple OAuth login handler improperly trusts email addresses from request parameters when the Apple JWT lacks an email claim. Attackers can forge Apple JWTs without email addresses and supply arbitrary emails to take over existing accounts or create new ones.

MitigationUpgrade Rocket.Chat to version 7.10.13, 8.0.7, or higher (8.1.6/8.2.6/8.3.6/8.4.4/8.5.1 depending on your branch). Until patched, disable Apple OAuth login.

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

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
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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

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. Identify Rocket.Chat installation
    Look for Rocket.Chat process running (e.g., 'ps aux | grep rocket' or 'docker ps' if containerized) or check common installation paths like /opt/Rocket.Chat, /var/www/rocket.chat, or the MongoDB database connection.
    Affected if Rocket.Chat is not installed or not running
  2. Determine Rocket.Chat version
    Run 'curl https://<your-rocket-chat-url>/api/info' or check the admin panel under 'Administration > Info' to see the installed version number.
    Affected if Version matches vulnerable ranges: 7.x before 7.10.13, 8.0.x before 8.0.7, 8.1.x before 8.1.6, 8.2.x before 8.2.6, 8.3.x before 8.3.6, 8.4.x before 8.4.4, or 8.5.x before 8.5.1
  3. Check if Apple OAuth is configured
    Navigate to 'Administration > OAuth > Apple' in the Rocket.Chat admin panel, or inspect the database collection 'oauth_services' to see if an Apple provider entry exists with 'enabled: true'.
    Affected if Apple OAuth login is enabled in the Rocket.Chat deployment
  4. Verify Apple OAuth is in use
    Review server logs for Apple OAuth login attempts (look for 'Apple' or 'apple' in authentication logs), or check if any users have registered using Apple as their login method.
    Affected if Apple OAuth has been used or is available as a login method

You are affected if running a Rocket.Chat version prior to the fixed releases (7.10.13, 8.0.7, 8.1.6, 8.2.6, 8.3.6, 8.4.4, or 8.5.1) AND Apple OAuth login is enabled in your environment.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Rocket.Chat to version 7.10.13, 8.0.7, or higher (8.1.6/8.2.6/8.3.6/8.4.4/8.5.1 depending on your branch). Until patched, disable Apple OAuth login.

Recommended fix High confidence

Upgrade to Rocket.Chat 8.5.1 (or the latest 8.x release >= 8.5.1, or 7.10.13 for the 7.x branch)

  1. 1. Identify the current Rocket.Chat version by checking the admin panel or running `rocket.Chat --version`
  2. 2. If running a version below 7.10.13, 8.0.7, 8.1.6, 8.2.6, 8.3.6, 8.4.4, or 8.5.1, plan an upgrade to one of these fixed versions
  3. 3. Back up the Rocket.Chat database and configuration files before upgrading
  4. 4. For Docker deployments: stop the container, pull the new image tag (e.g., `rocket.chat:8.5.1`), and restart the container
  5. 5. For non-Docker deployments: follow the official upgrade documentation for your package manager (snap, apt, yum, or npm)
  6. 6. After upgrade, verify the Apple OAuth login flow works correctly and test that email validation is enforced properly
Caveat Review the release notes for the target version to check for any breaking changes or migration requirements before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
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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-2026-55666 in production — separate from our analysis above.

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What this is

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What belongs here
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  • 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