Is CVE-2026-62643 actively exploited?

No active exploitation of CVE-2026-62643 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-62643 be exploited remotely?

Yes. CVE-2026-62643 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-62643?

CVE-2026-62643 has a CVSS score of 10.0 (CRITICAL).

HOME VULNERABILITIESCVE-2026-62643

CRITICAL

CVE-2026-62643

CWE-918Published: July 14, 2026· Updated: Jul 20, 2026

10.0

CVSS v3.1

Official Description

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. NOTE: this issue exists because of insufficient fixes for CVE-2026-35540 and CVE-2026-48843.

NVD Source

Risk Analysis

Insufficient CSS sanitization in Roundcube Webmail allows for SSRF or information disclosure when processing HTML emails. This critical vulnerability is a result of incomplete fixes for previous issues.

No public exploit is known, and it is not in KEV. It is remotely exploitable.

Recommended Action

Upgrade to the latest version of Roundcube Webmail to ensure proper CSS sanitization.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2026-62643 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 10.0.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.