MybbApplication

CVE-2019-3579

MEDIUM · 5.3 CVSS v3.1 Published 2019-06-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges 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
MyBB 1.8.19 allows remote attackers to obtain sensitive information because it discloses the username upon receiving a password-reset request that lacks the code parameter.

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 · moderate confidence

MyBB 1.8.19 contains an information disclosure vulnerability in its password reset functionality. When a password-reset request is submitted without the required security code parameter, the application erroneously discloses the username associated with the account, allowing remote attackers to enumerate valid usernames.

MitigationApply the vendor patch for MyBB 1.8.19 which modifies the password reset handler to reject or process requests uniformly without revealing whether a username exists in the system.

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
MybbApplication
Affected:= 1.8.19

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
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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. Confirm MyBB version
    Check the version of your installed MyBB forum software. This is typically visible in the admin dashboard under Dashboard > Home > Overview, or by viewing the inc/version.php file.
    Affected if The installed version is exactly 1.8.19
  2. Locate password reset handler
    Identify the password reset script in your MyBB installation. This is typically member.php (the forgot password function) or a related handler in the member directory.
    Affected if The password reset functionality exists in the expected location
  3. Test password reset without security code
    Submit a password reset request using the member.php?action=lostpw (or similar endpoint) with a valid username but deliberately omit the required security code parameter. Capture and examine the HTTP response.
    Affected if The response reveals whether the submitted username exists in the system (e.g., different error messages for existing vs. non-existing users, or username displayed in the response)
  4. Compare responses for valid vs invalid usernames
    Submit two password reset requests: one with a known-valid username and one with a random nonexistent username, both without the security code. Compare the responses.
    Affected if The application returns distinguishable responses that allow an attacker to determine if a username is valid in the system

User is affected if running MyBB 1.8.19 and the password reset endpoint leaks username existence information when the security code parameter is omitted, allowing username enumeration.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch for MyBB 1.8.19 which modifies the password reset handler to reject or process requests uniformly without revealing whether a username exists in the system.

Fix this in Mybb Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-3579 — 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-2019-3579 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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