Is CVE-2026-62642 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-62642 being exploited in the wild.

How severe is CVE-2026-62642?

Medium severity, with a CVSS score of 4.3, published 14 July 2026.

Which products and versions are affected?

Roundcube Webmail before 1.6.17, 1.7.x before 1.7.2.

Is there a fix for CVE-2026-62642?

A patch was published on 2026-07-05: Security updates 1.6.17 and 1.7.2 released by vendor. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-62642 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-62642?

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.

CVE-2026-62642: Roundcube Webmail infinite loop in TNEF decoder

CVE-2026-62642 · Severity: medium · CVSS 4.3 · Published 2026-07-14

Roundcube Webmail, a widely used browser-based email client, is vulnerable to a denial-of-service attack. An attacker can send a specially crafted email with a TNEF (winmail.dat) attachment that, when opened by a user, causes the mail server to enter an infinite loop. This can lead to service instability or unavailability for the affected user or the entire webmail instance.

Technologies: Roundcube Webmail. Vendors: Roundcube.

Quick answers

Is CVE-2026-62642 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-62642 being exploited in the wild.
How severe is CVE-2026-62642?: Medium severity, with a CVSS score of 4.3, published 14 July 2026.
Which products and versions are affected?: Roundcube Webmail before 1.6.17, 1.7.x before 1.7.2.
Is there a fix for CVE-2026-62642?: A patch was published on 2026-07-05: Security updates 1.6.17 and 1.7.2 released by vendor. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-62642 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-62642?: 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 vulnerability classified as CWE-835 (Loop with Unreachable Exit Condition) exists in the TNEF (winmail.dat) decoder of Roundcube Webmail. The flaw is located in the rcube_tnef_decoder.php component. An unauthenticated remote attacker can exploit this by sending an email containing a malformed TNEF attachment. When a user attempts to view the email, the decoder enters an infinite loop, consuming system resources and resulting in a Denial of Service (DoS). The issue is addressed in versions 1.6.17 and 1.7.2.

Affected products

Roundcube Webmail before 1.6.17, 1.7.x before 1.7.2

Timeline

2026-07-05: patched: Security updates 1.6.17 and 1.7.2 released by vendor.
2026-07-14: advisory: CVE published to NVD.

References

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