# CVE-2026-114726: Roundcube Webmail mail header injection in Bounce action

Source: https://junglewise.ai/threats/cve-2026-114726-roundcube-webmail-before-1-6-20-and-1-7-x-before-1-7-5-is  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-22. Updated: 2026-10-22  
License: CC BY 4.0 with a link back

CVE-2026-114726 · Severity: medium · CVSS 5.8 · Published 2026-10-22

Roundcube Webmail is a web-based email client used by organizations and individuals to access their email. A flaw in the Bounce (resend) action allows an attacker to inject arbitrary email headers into messages when a user forwards or resends a crafted email, potentially enabling spam, phishing, or credential theft through forged message headers.

Technologies: [Roundcube Webmail](https://junglewise.ai/threats/technologies/webmail). Vendors: [Roundcube](https://junglewise.ai/threats/vendors/roundcube).

## Quick answers

**Is CVE-2026-114726 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114726 being exploited in the wild.

**How severe is CVE-2026-114726?** Medium severity, with a CVSS score of 5.8, published 22 October 2026.

**Which products and versions are affected?** Roundcube Webmail before 1.6.20, 1.7.x before 1.7.5.

**Is there a fix for CVE-2026-114726?** Yes: fixed in 1.6.20, 1.7.5. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114726 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-114726?** 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.

## How to fix

- Fixed in 1.6.20, 1.7.5

## Technical details

The vulnerability exists in rcube_mime::decode_address_list(), which fails to strip control characters (CRLF sequences) from decoded display names. When a received email has CRLF characters encoded in the From display-name header, an attacker can inject arbitrary mail headers into the message the user bounces or resends. This is a classic mail header injection attack that requires user interaction (the victim must bounce/resend the malicious message) and can result in forged email headers.

## Affected products

- Roundcube Webmail before 1.6.20, 1.7.x before 1.7.5

## Timeline

- 2026-10-22: disclosed
- 2026-10-19: patched

## References

- [https://bugs.debian.org/1151279](https://bugs.debian.org/1151279)
- [https://github.com/roundcube/roundcubemail/commit/3a136465c965776a5f636587187626985dae4f3b](https://github.com/roundcube/roundcubemail/commit/3a136465c965776a5f636587187626985dae4f3b)

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