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Pale MoonApplication · Palemoon

CVE-2020-9545

HIGH · 7.5 CVSS v3.1 Published 2020-03-02
Fix available
A fix is available. Upgrade to 28.8.4 or later.
See remediation →
84/100
Remediation priority · High
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
Pale Moon 28.x before 28.8.4 has a segmentation fault related to module scripting, as demonstrated by a Lacoste web site.

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

A segmentation fault vulnerability exists in Pale Moon browser versions 28.x before 28.8.4, triggered during module scripting operations. The crash occurs when visiting a malicious website containing specially crafted module script content, indicating a memory handling flaw in the browser's JavaScript module loading mechanism.

MitigationUpgrade Pale Moon to version 28.8.4 or later. Until updated, avoid visiting untrusted websites or disable JavaScript execution as a defensive measure.

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
Pale MoonApplication
Affected:>= 28.0, < 28.8.4

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Pale Moon version
    Open Pale Moon, go to Help > About Pale Moon, or look at the application binary properties. The version number is displayed in the About window.
    Affected if The version shown is 28.0, 28.1.x, 28.2.x, 28.3.x, 28.4.x, 28.5.x, 28.6.x, 28.7.x, or any 28.8.0-28.8.3 release (anything below 28.8.4).
  2. Confirm JavaScript is enabled in the browser
    Go to Tools > Options > Content, or enter about:config in the address bar and search for javascript.enabled. Verify the setting is true.
    Affected if JavaScript is enabled (javascript.enabled = true), as the vulnerability is triggered through malicious module script content loaded via JavaScript.
  3. Check for any custom content security policies
    In about:config, search for security.csp. Inspect whether custom policies exist that might restrict module script loading.
    Affected if No restrictive Content Security Policy is set that blocks module scripts, as the exploit requires the browser to process module script content.

You are affected if your Pale Moon version is 28.0 or any version from 28.1.0 through 28.8.3, and JavaScript execution is enabled in the browser settings.

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 28.8.4 or later
Fixed in 28.8.4
Interim mitigation

Upgrade Pale Moon to version 28.8.4 or later. Until updated, avoid visiting untrusted websites or disable JavaScript execution as a defensive measure.

Fix this in Pale Moon Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.

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-2020-9545 in production — separate from our analysis above.

No notes yet

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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