dbcve.org
FirefoxWeb browser · Mozilla

CVE-2025-49710

CRITICAL · 9.8 CVSS v3.1 Published 2025-06-11
Fix available
A fix is available. Upgrade to 139.0.4 or later.
See remediation →
100/100
Remediation priority · Urgent
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
An integer overflow was present in `OrderedHashTable` used by the JavaScript engine. This vulnerability was fixed in Firefox 139.0.4.

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

An integer overflow vulnerability exists in the OrderedHashTable data structure within Firefox's JavaScript engine (SpiderMonkey). This could lead to memory corruption and potentially allow remote code execution when processing specially crafted JavaScript content.

MitigationUpdate Firefox to version 139.0.4 or later to remediate this critical vulnerability.

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
FirefoxWeb browser
Affected:< 139.0.4

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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. Check installed Firefox version
    Open Firefox, click the menu button (three horizontal lines), select Help, then About Firefox. The version number is displayed in the dialog that opens.
    Affected if The displayed version is below 139.0.4 (for example, 139.0.3, 139.0, 138.x, or earlier)
  2. Verify version via command line
    Run 'firefox --version' in terminal/command prompt, or on Windows check the executable properties of firefox.exe in the program directory.
    Affected if The reported version is lower than 139.0.4

If Firefox version is below 139.0.4, the environment is affected by this integer overflow vulnerability in the JavaScript engine's OrderedHashTable component.

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
Upgrade available Upgrade to 139.0.4 or later
Fixed in 139.0.4
Interim mitigation

Update Firefox to version 139.0.4 or later to remediate this critical vulnerability.

Recommended fix High confidence

Firefox 139.0.4

  1. Check current Firefox version via Help > About Firefox or running 'firefox --version' in terminal
  2. Download Firefox 139.0.4 or later from the official Mozilla website (www.mozilla.org)
  3. Install the Firefox 139.0.4 update
  4. Restart Firefox to complete the update process

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

Fix this in Firefox 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
Get the upgrade done

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-2025-49710 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2025-49710 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