FirefoxWeb browser · Mozilla
CVE-2024-5695
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 · uneditedIf an out-of-memory condition occurs at a specific point using allocations in the probabilistic heap checker, an assertion could have been triggered, and in rarer situations, memory corruption could have occurred. This vulnerability affects Firefox < 127.
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 confidenceFirefox's probabilistic heap checker has a vulnerability where an out-of-memory condition at a specific point during allocations can trigger an assertion failure or, less commonly, memory corruption. This is a memory safety issue in the browser's heap verification logic that can be exploited when the browser encounters OOM conditions.
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
< 127.0CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check if Firefox is installedLook for Firefox in the system. On Windows, check Program Files or Program Files (x86) for Mozilla Firefox folder. On macOS, check /Applications for Firefox.app. On Linux, check /usr/lib/firefox or use package manager.Affected if Firefox is present on the system
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Determine installed Firefox versionOpen Firefox, click the menu button (three horizontal lines), select Help, then About Firefox. Alternatively, navigate to about:support in the address bar. The version number is displayed on the page.Affected if Version shown is less than 127 (e.g., 126.x, 126.0.1, etc.)
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Verify OOM trigger conditionThe vulnerability triggers during out-of-memory conditions when the probabilistic heap checker encounters a specific allocation failure. This is an internal browser condition that cannot be directly tested without causing the OOM.Affected if Any Firefox version below 127 is potentially affected when the browser experiences OOM conditions during normal use
User is affected if Firefox version is below 127; the vulnerability automatically becomes relevant during any OOM condition the browser encounters.
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 · scoped127.0
Upgrade Firefox to version 127 or later. Organizations should deploy the updated browser version through their standard patch management processes.
Firefox 127
- Back up any important data and bookmarks in your current Firefox installation
- Download Firefox 127 or later from the official Mozilla website (www.mozilla.org)
- Close all running Firefox instances
- Install Firefox 127 over your current version, or use your system's package manager to update to version 127 or later
- After installation, launch Firefox and verify the version number in Help > About Firefox to confirm version 127 or newer is installed
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-2024-5695 — 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-2024-5695 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
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