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GHSA-x4q5-8j5g-hpjc

MEDIUM

GHSA-x4q5-8j5g-hpjc is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in roundcube/roundcubemail. O3 Security confirms whether GHSA-x4q5-8j5g-hpjc is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Roundcube Webmail: Insufficient HTML attachment sanitization in preview mode

Also known asCVE-2026-35539
Published
Apr 3, 2026
Updated
Apr 4, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐘roundcube/roundcubemail

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistroundcube/roundcubemail1.7-beta&&< 1.7-rc51.7-rc5

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for roundcube/roundcubemail. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update roundcube/roundcubemail to 1.7-rc5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x4q5-8j5g-hpjc is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-x4q5-8j5g-hpjc is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-x4q5-8j5g-hpjc. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
O3 Security · Impact-Aware SCA

Is GHSA-x4q5-8j5g-hpjc in your dependencies?

O3 detects GHSA-x4q5-8j5g-hpjc across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.