# CVE-2026-49103: Webmin path traversal in mailboxes component

Source: https://junglewise.ai/threats/cve-2026-49103-webmin-path-traversal-in-mailboxes-component  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-27. Updated: 2026-05-27  
License: CC BY 4.0 with a link back

CVE-2026-49103 · Severity: info · CVSS 9.4 · Published 2026-05-27

Webmin, a popular web-based interface for system administration, contains a security flaw in its mailboxes component. An attacker with low-level access can exploit this to save email attachments to unauthorized locations on the server. This could lead to a full system takeover, data loss, or the corruption of critical system files.

Technologies: [Webmin](https://junglewise.ai/threats/technologies/webmin). Vendors: [Webmin](https://junglewise.ai/threats/vendors/webmin).

## Quick answers

**Is CVE-2026-49103 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49103 being exploited in the wild.

**How severe is CVE-2026-49103?** Informational severity, with a CVSS score of 9.4, published 27 May 2026.

**Which products and versions are affected?** Webmin < 2.640.

**Is there a fix for CVE-2026-49103?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-49103 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-49103?** Check whether you run Webmin 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 path traversal vulnerability (CWE-24) exists in Webmin's mailboxes component, specifically within 'mailboxes/detachall.cgi' and 'mailboxes/detach.cgi'. The application fails to properly sanitize filenames when saving email attachments, allowing an authenticated user with mailbox access to use '../' sequences to write files outside of the intended directory. This can be leveraged to overwrite sensitive system files or achieve remote code execution. The issue is resolved in Webmin version 2.640.

## Affected products

- Webmin Webmin < 2.640

## Timeline

- 2026-05-27: disclosed
- 2026-05-27: advisory

## References

- [https://github.com/webmin/webmin/commit/cf432879a14568c4bb44cd2f9e5a9bd0e168edc1](https://github.com/webmin/webmin/commit/cf432879a14568c4bb44cd2f9e5a9bd0e168edc1)
- [https://github.com/webmin/webmin/compare/2.630...2.640](https://github.com/webmin/webmin/compare/2.630...2.640)

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