MailGates: Improper Neutralization of CRLF Sequences
CVE-2026-6351 is a high-severity improper neutralization of CRLF sequences vulnerability in MailGates from Openfind, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 6.1.10.054, 5.2.10.099 as the first without the flaw, so updating MailGates to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update MailGates to 6.1.10.054 or 5.2.10.099, whichever matches your release line, or a later version.
- Update MailAudit to 6.1.10.054 or 5.2.10.099, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Openfind | MailGates | 6.0 up to, but not including, 6.1.10.054; 5.0 up to, but not including, 5.2.10.099 | 6.1.10.054, 5.2.10.099 |
| Openfind | MailAudit | 6.0 up to, but not including, 6.1.10.054; 5.0 up to, but not including, 5.2.10.099 | 6.1.10.054, 5.2.10.099 |
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (cert.org.tw).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (cert.org.tw) |
| CVSS 3.1 | 7.5 | High | CNA (cert.org.tw) |
Official description
MailGates/MailAudit developed by Openfind has a CRLF Injection vulnerability, allowing unauthenticated remote attackers to exploit this vulnerability to read system files.
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: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in MailGates
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Neutralization of CRLF Sequences vulnerabilities
- 8.6 High severity
- 9.8 Critical severity
- 10.0 Critical severity
- 8.6 High severity
- 8.7 High severity
- 7.5 High severity
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