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FirefoxWeb browser · Mozilla

CVE-2019-11740

HIGH · 8.8 CVSS v3.1 Published 2019-09-27
Fix available
A fix is available. Upgrade to 60.9.0 / 68.1.0 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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
Mozilla developers and community members reported memory safety bugs present in Firefox 68, Firefox ESR 68, and Firefox 60.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.

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 · moderate confidence

Memory safety bugs in Firefox and Thunderbird that allow memory corruption and potentially arbitrary code execution via crafted web content.

MitigationUpgrade affected software to patched versions: Firefox 69+, Thunderbird 68.1+/60.9+, Firefox ESR 68.1+/60.9+.

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:< 60.9.0< 69.0
Firefox EsrWeb browser
Affected:>= 68.0, < 68.1.0
Ubuntu LinuxOperating system
Affected:= 16.04= 18.04= 19.04
ThunderbirdApplication
Affected:< 60.9.0>= 68.0, < 68.1.0
LeapOperating system
Affected:= 15.0= 15.1

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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, navigate to Menu > Help > About Firefox, or run `firefox --version` from command line
    Affected if Version is below 60.9.0, or between 60.9.0 and 68.x (inclusive of 68.0 but below 68.1), or below 69.0 for non-ESR versions before 60.9.0
  2. Check installed Firefox ESR version
    Open Firefox ESR, navigate to Menu > Help > About Firefox ESR, or run `firefox-esr --version` from command line
    Affected if Version is 68.0 through 68.0.x (anything >= 68.0 but < 68.1.0)
  3. Check installed Thunderbird version
    Open Thunderbird, navigate to Menu > Help > About Thunderbird, or run `thunderbird --version` from command line
    Affected if Version is below 60.9.0, or between 60.9.0 and 68.x (inclusive of 68.0 but below 68.1)
  4. Check Ubuntu system packages for Firefox/Thunderbird
    Run `dpkg -l | grep firefox` or `dpkg -l | grep thunderbird` on Debian/Ubuntu systems
    Affected if Installed package version corresponds to vulnerable Firefox/Thunderbird versions per the affected ranges above

You are affected if any installed Firefox or Thunderbird version falls within the vulnerable ranges: Firefox < 60.9.0, Firefox < 69.0, Firefox ESR 68.0-68.0.x, Thunderbird < 60.9.0, or Thunderbird 68.0-68.0.x.

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 60.9.0 / 68.1.0 / 69.0 or later
Fixed in 60.9.068.1.069.0
Interim mitigation

Upgrade affected software to patched versions: Firefox 69+, Thunderbird 68.1+/60.9+, Firefox ESR 68.1+/60.9+.

Fix this in Firefox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $910
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,456.

Scan for this in your stack

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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-2019-11740 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