KmailApplication · Kde

CVE-2016-7968

MEDIUM · 6.5 CVSS v3.0 Published 2016-12-23
Fix available
A fix is available. Upgrade to after 5.3.0 or later.
See remediation →
74/100
Remediation priority · Elevated
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
KMail since version 5.3.0 used a QWebEngine based viewer that had JavaScript enabled. HTML Mail contents were not sanitized for JavaScript and included code was executed.

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 confidence

KMail versions 5.3.0 and later used a QWebEngine-based HTML email viewer with JavaScript enabled. The application failed to sanitize HTML email content before rendering, allowing embedded JavaScript to execute within the email viewer context (stored XSS). This could enable attackers to execute arbitrary JavaScript in the context of the victim's KMail session by sending specially crafted HTML emails.

MitigationUpgrade to a patched version of KMail that either disables JavaScript in QWebEngine or implements proper HTML sanitization before rendering email content. As a temporary workaround, disable HTML email rendering and use plain text view.

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
KmailApplication
Affected:<= 5.3.0

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
Low
Integrity
Low
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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 KMail version
    Run 'kmail --version' or 'apt list --installed 2>/dev/null | grep -i kmail' or look in KDE System Settings > Application Info
    Affected if Version is 5.3.0 or lower (the version number equals or is less than the affected range)
  2. Verify HTML email rendering is enabled
    Open KMail, go to Settings > Configure KMail > Reading > Messages, or inspect the configuration file ~/.config/kmail2rc for 'HTML Reader' or 'useHTML' settings
    Affected if HTML rendering is turned ON (the vulnerability only applies when HTML emails are rendered)
  3. Confirm QWebEngine viewer is in use
    In KMail settings under Reading > Messages, check if 'Use fallback web engine when possible' or similar QWebEngine-based viewer is selected
    Affected if QWebEngine-based HTML viewer is selected (this is the vulnerable component)

You are affected if your KMail version is 5.3.0 or lower AND you have HTML email rendering enabled with the QWebEngine viewer selected.

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 a release after 5.3.0
Interim mitigation

Upgrade to a patched version of KMail that either disables JavaScript in QWebEngine or implements proper HTML sanitization before rendering email content. As a temporary workaround, disable HTML email rendering and use plain text view.

Fix this in Kmail Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2016-7968 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