FirefoxWeb browser · Mozilla
CVE-2023-4048
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 · uneditedAn out-of-bounds read could have led to an exploitable crash when parsing HTML with DOMParser in low memory situations. This vulnerability affects Firefox < 116, Firefox ESR < 102.14, and Firefox ESR < 115.1.
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 confidenceOut-of-bounds read vulnerability in Firefox's DOMParser when parsing HTML in low memory situations, potentially allowing an exploitable crash. The vulnerability exists in the browser's HTML parsing logic and affects multiple Firefox and Firefox ESR versions.
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
< 116.0>= 102.0, < 102.14>= 115.0, < 115.1
Debian LinuxOperating system
= 10.0= 11.0= 12.0CVSS 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
- 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 Firefox version via command lineRun `firefox --version` or `firefox-esr --version` in terminalAffected if Version output is less than 102.14, or between 115.0 and 115.1 exclusive, or less than 116.0 (checking against all affected ranges)
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Check Firefox version via browser UIOpen Firefox, type `about:firefox` in the address bar and press EnterAffected if Version displayed is within the affected ranges: < 102.14, >= 102.0 to < 102.14, >= 115.0 to < 115.1, or < 116.0
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Check installed package version on Debian systemsRun `dpkg -l | grep -i firefox` or `apt list --installed | grep -i firefox`Affected if Package version corresponds to Firefox versions that are vulnerable per the affected ranges
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Verify DOMParser usage contextThis vulnerability triggers when parsing HTML with DOMParser in low memory conditions - no specific feature toggle exists, it is inherent to the parsing codeAffected if Any use of DOMParser to parse HTML content in affected Firefox versions could trigger the condition
User is affected if Firefox or Firefox ESR installed version falls within 102.0 to 102.13, 115.0, or any version below 116.0 (outside the patched releases 102.14, 115.1, and 116.0+)
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 · scoped102.14115.1116.0
Update Firefox to version 116 or later, or Firefox ESR to 102.14/115.1 or later to patch the vulnerability.
Firefox 116.0 (or Firefox ESR 102.14/115.1 depending on ESR branch)
- For Firefox (standard edition): Upgrade to Firefox 116.0 or later
- For Firefox ESR 102.x branch: Upgrade to Firefox ESR 102.14 or later
- For Firefox ESR 115.x branch: Upgrade to Firefox ESR 115.1 or later
- On Debian systems: Run 'apt update && apt upgrade firefox' to apply the patched package
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Firefox
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 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 $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-4048 — 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-2023-4048 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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