Mail header injection in Roundcube Webmail via forwarded attachments
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
Roundcube Webmail from 1.6.0 before 1.6.20 and from 1.7.0 before 1.7.5 contains a mail header injection flaw when a message is forwarded as an attachment. The subject of the forwarded message is used unchanged to build the attachment name, so a received message whose subject contains CRLF sequences can add arbitrary MIME part headers to the outgoing message (CWE-99). An unauthenticated remote attacker can exploit this by sending a crafted message that a user later forwards as an attachment, which can alter the integrity of the forwarded message.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a mail header injection vulnerability when a message is forwarded as an attachment. The subject of the forwarded message was used verbatim to generate the attachment name, so a received message whose subject contains CRLF sequences could inject arbitrary MIME part headers into the outgoing message. Upstream fixed this in the commit “Fix mail header injection via subject of a message forwarded as attachment”, which collapses whitespace in the generated name.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Roundcube Webmail to 1.6.20 or 1.7.5. The sources list no fixed version for other products.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Webmail (Roundcube) Fixed in 1.6.20, 1.7.5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Roundcube Webmail — roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1…
20 records Highest priority Priority LOW 20 LOW
Other records, highest priority first
- TI-2026-79180 Server-side request forgery filter bypass in Roundcube WebmailPriority LOW 38
- TI-2026-79177 Roundcube Webmail passes unsafe SVG and EPS content to ImageMagickPriority LOW 38
- TI-2026-79182 Improper authentication in Roundcube Webmail multi-host alias loginsPriority LOW 37
Vendor assessments
Timeline
- 2026-10-22 Threatist record created from CVE-2026-114717
- 2026-10-22 Alias added: GHSA-8246-wqv2-g48f
- 2026-10-26 CISA SSVC decision points changed
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-30 CVSS score added · NVD
References
Patch 4
- https://github.com/roundcube/roundcubemail/commit/4c3291ce9df9e1d3b45330d0854d65cd8efbeee9
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.5
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.20
- https://github.com/roundcube/roundcubemail/commit/c325953a251d0132f1909569b3eac0b974095dd4
More Roundcube Webmail vulnerabilities
- TI-2025-31204 Deserialization of untrusted data in Roundcube Webmail KEVCVSS 3.1CRITICAL 9.9
- TI-2021-19778 Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to a potential SQL injection via search or search_params. KEVCVSS 3.1CRITICAL 9.8
- TI-2020-10051 rcube_image.php in Roundcube Webmail before 1.4.4 allows attackers to execute arbitrary… KEVCVSS 3.1CRITICAL 9.8
- TI-2024-28025 A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7… KEVCVSS 3.1CRITICAL 9.3
- TI-2017-12250 Roundcube Webmail before 1.1.10, 1.2.x before 1.2.7, and 1.3.x before 1.3.3 allows… KEVCVSS 3.1HIGH 7.8
- TI-2025-41994 Cross-site scripting in Roundcube Webmail KEVCVSS 3.1HIGH 7.2
Sources
- CVE-2026-114717 · CVE Program
- CVE-2026-114717 · NVD
- FIRST EPSS
- GHSA-8246-wqv2-g48f · GitHub Advisory Database · CC BY 4.0
- CVE-2026-114717 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences