Webmail: Improper Neutralization of CRLF Sequences
CVE-2026-113386 is a high-severity improper neutralization of CRLF sequences vulnerability in Webmail from Roundcube, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 1.6.20, 1.7.5 as the first without the flaw, so updating Webmail to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1% chance of exploitation within 30 days, higher than 63% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Webmail to 1.6.20 or 1.7.5, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Roundcube | Webmail | 1.6.0 up to, but not including, 1.6.20; 1.7.0 up to, but not including, 1.7.5 | 1.6.20, 1.7.5 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N. Scored by CNA (mitre.org).
Official description
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 are affected by IMAP command injection. A remote authenticated attacker can exploit this via CRLF sequences injected into the _uid parameter of the mail/headers and mail/viewsource actions to execute arbitrary IMAP commands.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of CRLF Sequences
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
How developers prevent this class of flaw
- Appropriately filter or quote CRLF sequences in user-controlled input.
More Improper Neutralization of CRLF Sequences vulnerabilities (CWE-93)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/roundcube/roundcubemail/commit/004adaaeca4f6799715a54d12e3f657f19efcc9a
- github.com/roundcube/roundcubemail/commit/bf5bc0266a8cd16be6b640409e64a6c6c2705049
- github.com/roundcube/roundcubemail/commit/f62879defc0330ae240c72b83b2d00a8ab337447
- github.com/roundcube/roundcubemail/releases/tag/1.6.20
- github.com/roundcube/roundcubemail/releases/tag/1.7.5
Other references
Other vulnerabilities in Webmail
- 8.1 High severity
- 7.2 High severity
- 8.3 High severity
- 8.1 High severity
- 7.1 High severity
- 8.5 High severity
Recent Improper Neutralization of CRLF Sequences vulnerabilities
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 9.4 Critical severity
- 9.9 Critical severity
- 7.8 High severity
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