CVE-2026-114717: CWE-99 Improper Control of Resource Identifiers ('Resource Injection') in Roundcube Webmail
Description
CVE-2026-114717 is a mail header injection vulnerability in Roundcube Webmail versions before 1.6.20 and 1.7.x before 1.7.5. The flaw occurs when forwarding a message as an attachment, where the subject line is used directly to name the attachment. If the subject contains CRLF sequences, it can inject arbitrary MIME headers into the outgoing message. This issue has been fixed by collapsing whitespace in the generated attachment name.
CVSS v3.1
Score 4.0medium
Affected software
Roundcube
Webmail
pkg:github/WebmailRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Roundcube Webmail versions >=1.6.0 <1.6.20 and >=1.7.0 <1.7.5 are vulnerable to a mail header injection (CWE-99) when forwarding messages as attachments. The vulnerability arises because the subject of the forwarded message is used verbatim to generate the attachment name. If the subject contains CRLF sequences, an attacker can inject arbitrary MIME part headers into the outgoing message. The upstream fix involved collapsing whitespace in the generated attachment name to prevent injection.
Potential Impact
The vulnerability allows an attacker to inject arbitrary MIME headers into forwarded messages by exploiting CRLF sequences in the subject line. This can lead to message manipulation or spoofing, potentially affecting the integrity of forwarded emails. The CVSS score is 4.0 (medium severity) with no confidentiality or availability impact, but limited integrity impact.
Mitigation Recommendations
A fix is available and has been implemented upstream by collapsing whitespace in the generated attachment name to prevent mail header injection. Users should upgrade Roundcube Webmail to versions 1.6.20 or later, or 1.7.5 or later to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-10-22T01:21:14.433Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad967fa4d27ba8daa1a2824
Added to database: 10/22/2026, 01:33:46 UTC
Last enriched: 10/22/2026, 02:31:19 UTC
Last updated: 10/22/2026, 02:31:19 UTC
Views: 2
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