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WebmailApplication · Roundcube

CVE-2026-54433

CRITICAL · 10.0 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 1.6.17 / 1.7.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 5 weeks old

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
In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's authenticated session simply by opening or previewing the message (zero-click).

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

Roundcube Webmail fails to properly sanitize plain-text email content, allowing attackers to embed malicious JavaScript in email bodies. When authenticated users open or preview these crafted emails, the embedded script executes in their session context, enabling session hijacking, data theft, or further network compromise.

MitigationUpgrade Roundcube Webmail to version 1.6.17 or 1.7.2 or later to obtain the security patch. Consider disabling HTML email rendering as a defense-in-depth measure until the update is applied.

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
WebmailApplication
Affected:< 1.6.17>= 1.7.0, < 1.7.2

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
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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. Determine installed Roundcube Webmail version
    Check the version file in the Roundcube installation directory, typically found in program/include/rcmail.php or program/version.php, or view the version displayed on the Roundcube login page footer.
    Affected if The installed version is less than 1.6.17 OR greater than or equal to 1.7.0 but less than 1.7.2.
  2. Verify email display configuration
    Examine the Roundcube configuration file (config/config.inc.php or config/defaults.inc.php) for the $config['htmleditor'] setting which controls how emails are rendered.
    Affected if The htmleditor setting is set to 1 (always) or 2 (reply forward), enabling HTML rendering of plain-text emails.
  3. Check for plain-text email rendering
    Review the Roundcube configuration for the $config['force_7bit'] setting and verify if plain-text emails are being automatically converted to HTML for display.
    Affected if force_7bit is disabled (set to false) and plain-text emails are being rendered in HTML format, allowing script execution.
  4. Review email preview settings
    Check if the preview pane feature is enabled in Roundcube settings, which can automatically render email content when selected.
    Affected if Preview pane is enabled, causing emails to render automatically without explicit user action.

You are affected if your Roundcube Webmail version falls within the vulnerable range (< 1.6.17 or >= 1.7.0 and < 1.7.2) AND your configuration allows plain-text or non-HTML emails to be rendered in HTML format.

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.

dbcve · scoped
Upgrade available Upgrade to 1.6.17 / 1.7.2 or later
Fixed in 1.6.171.7.2
Interim mitigation

Upgrade Roundcube Webmail to version 1.6.17 or 1.7.2 or later to obtain the security patch. Consider disabling HTML email rendering as a defense-in-depth measure until the update is applied.

Recommended fix High confidence

Upgrade to Roundcube Webmail 1.6.17 or 1.7.2 (whichever branch matches your current installation)

  1. 1. Identify current Roundcube Webmail version by checking the installed version file or version() function
  2. 2. Create a complete backup of the Roundcube Webmail installation directory and database
  3. 3. If currently running version < 1.6.17, plan upgrade to version 1.6.17
  4. 4. If currently running version >= 1.7.0 and < 1.7.2, plan upgrade to version 1.7.2
  5. 5. Download the appropriate fixed release (1.6.17 or 1.7.2) from the official Roundcube repository at roundcube.net/download
  6. 6. Extract the new version files, preserving the config/ directory and any custom configurations
  7. 7. Run any included database migration scripts if present in the upgrade package
  8. 8. Clear cached templates and sessions to ensure new code is loaded

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Webmail Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,832.

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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-2026-54433 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