dbcve.org
FirefoxWeb browser · Mozilla

CVE-2025-8038

CRITICAL · 9.8 CVSS v3.1 Published 2025-07-22
Fix available
A fix is available. Upgrade to 140.1.0 / 141.0 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
Thunderbird ignored paths when checking the validity of navigations in a frame. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.

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

Thunderbird had a frame navigation validation flaw where it ignored paths when checking the validity of navigations in a frame. This could allow an attacker to manipulate frame navigations, potentially leading to clickjacking or unauthorized navigation attacks.

MitigationUpdate Thunderbird to version 140.1 or 141 (or later) to receive the fix for this frame navigation validation bypass 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:< 140.1.0< 141.0
ThunderbirdApplication
Affected:< 140.1.0< 141.0

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 Thunderbird version
    Open Thunderbird, go to Help > About Thunderbird (or on macOS Thunderbird > About Thunderbird). The version number is displayed in the dialog.
    Affected if The displayed version is lower than 140.1.0 or between 140.x (excluding 140.1.0) and 141.0
  2. Check installed Firefox version (if applicable)
    Open Firefox, click the menu button (three lines), then Help > About Firefox. The version number appears at the top.
    Affected if The displayed version is lower than 140.1.0 or between 140.x (excluding 140.1.0) and 141.0
  3. Identify email content handling (Thunderbird only)
    In Thunderbird, go to Account Settings > [select account] > Composition & Addressing. Check if 'Compose messages in HTML' is enabled.
    Affected if HTML composition is enabled and you view emails from untrusted sources, allowing embedded frames in email content
  4. Determine frame usage exposure
    This vulnerability affects any scenario where Thunderbird or Firefox processes web pages or HTML emails containing frame or iframe elements. Consider whether your typical email or web browsing involves content from untrusted sources.
    Affected if You regularly view HTML emails or visit websites that may contain frame/iframe elements from potentially malicious sources

You are affected if your Thunderbird version is below 140.1.0 or below 141.0, or your Firefox version is below 140.1.0 or below 141.0, and you handle content with embedded frames.

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 140.1.0 / 141.0 or later
Fixed in 140.1.0141.0
Interim mitigation

Update Thunderbird to version 140.1 or 141 (or later) to receive the fix for this frame navigation validation bypass vulnerability.

Recommended fix High confidence

Firefox 141 / Firefox ESR 140.1 / Thunderbird 141 / Thunderbird 140.1

  1. Check current Firefox or Thunderbird version by navigating to Menu > Help > About (or running: firefox --version or thunderbird --version)
  2. Download Firefox 141 (or Firefox ESR 140.1 for enterprise deployments) from the official Mozilla website at https://www.mozilla.org/en-US/firefox/releases/
  3. Download Thunderbird 141 (or Thunderbird 140.1) from the official Mozilla website at https://www.thunderbird.net/en-US/thunderbird/releases/
  4. Close all instances of Firefox or Thunderbird
  5. Run the downloaded installer and follow the prompts to complete the upgrade
  6. Restart the application and verify the version in Menu > Help > About confirms the upgrade was successful

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

Fix this in Firefox Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-8038 — 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-2025-8038 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