CVE-2026-48849: Roundcube Webmail stored XSS in draft restore dialog subject field

CVE-2026-48849 · Severity: medium · CVSS 4.4 · Published 2026-05-25

Roundcube Webmail, a widely used open-source web-based email client, is vulnerable to a security flaw that could allow an attacker to inject malicious scripts into shared mailboxes. By crafting a specific email subject line, an attacker could execute code in the browser of another user who interacts with a draft restoration prompt. This could lead to unauthorized access to email content or the hijacking of user sessions within the webmail interface.

Technologies: Roundcube Webmail. Vendors: Roundcube.

Quick answers

Is CVE-2026-48849 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48849 being exploited in the wild.
How severe is CVE-2026-48849?
Medium severity, with a CVSS score of 4.4, published 25 May 2026.
Which products and versions are affected?
Roundcube Webmail 1.6.x before 1.6.16, 1.7.x before 1.7.1.
Is there a fix for CVE-2026-48849?
A patch was published on 2026-05-24: Roundcube released versions 1.6.16 and 1.7.1 to address the issue. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48849 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-48849?
Check whether you run Roundcube Webmail at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stored cross-site scripting (XSS) vulnerability exists in Roundcube Webmail versions 1.6.x before 1.6.16 and 1.7.x before 1.7.1. The flaw is located in the draft restoration dialog, where the 'subject' field is not properly sanitized before being rendered in the UI. An authenticated attacker can exploit this by creating a draft with a malicious payload in the subject line; when another user (particularly in shared mailbox scenarios) attempts to restore that draft, the payload executes in their browser context. This allows for HTML/CSS injection and arbitrary JavaScript execution. The issue is addressed in versions 1.6.16 and 1.7.1.

Affected products

  • Roundcube Roundcube Webmail 1.6.x before 1.6.16, 1.7.x before 1.7.1

Timeline

  • 2026-05-24: patched: Roundcube released versions 1.6.16 and 1.7.1 to address the issue.
  • 2026-05-25: disclosed: CVE-2026-48849 was published.

References

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