FirefoxWeb browser · Mozilla
CVE-2023-5728
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 · uneditedDuring garbage collection extra operations were performed on a object that should not be. This could have led to a potentially exploitable crash. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.
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 confidenceA garbage collection vulnerability in Firefox and Thunderbird allowed extra operations to be performed on objects during GC that should not have been targeted, potentially leading to an exploitable crash. This is a memory safety issue in the JavaScript engine or DOM garbage collection subsystem.
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
< 119.0
Firefox EsrWeb browser
< 115.4
Debian LinuxOperating system
= 10.0= 11.0< 115.4.1CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 checksWork through these to decide whether this CVE applies to you.
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Check installed Firefox versionOpen Firefox, click Help > About Firefox to view the version number, or run 'firefox --version' in terminalAffected if version is below 119.0 (or below 115.4 for Firefox ESR)
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Check installed Thunderbird versionOpen Thunderbird, click Help > About Thunderbird to view the version number, or run 'thunderbird --version' in terminalAffected if version is below 115.4.1
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Check Firefox version on Debian systemsRun 'dpkg -l | grep firefox-esr' or 'apt-cache policy firefox-esr' to query the installed package versionAffected if installed version is below 115.4-1 (Debian packaged ESR)
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Check Thunderbird version on Debian systemsRun 'dpkg -l | grep thunderbird' or 'apt-cache policy thunderbird' to query the installed package versionAffected if installed version is below 1:115.4.1-1 (Debian packaged)
You are affected if you run any version of Firefox below 119.0 (or below 115.4 ESR), or Thunderbird below 115.4.1, regardless of OS platform.
Generated from the published advisory. Verify against your own configuration.
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 · scoped115.4115.4.1119.0
Update affected software to Firefox 119+, Firefox ESR 115.4+, or Thunderbird 115.4.1+ to receive the patch for this garbage collection memory safety issue.
Firefox 119.0, Firefox ESR 115.4, Thunderbird 115.4.1 (or later stable releases)
- Update Firefox to version 119.0 or later
- Update Firefox ESR to version 115.4 or later
- Update Thunderbird to version 115.4.1 or later
- On Debian systems, run 'apt update && apt upgrade' to apply security updates, or install the Debian security patches for this CVE
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
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 locallyCheck whether your project pulls in CVE-2023-5728 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-5728 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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