CVE-2026-111227: Improper Neutralization of CRLF Sequences ('CRLF Injection') in Netgate pfSense CE
Description
Netgate pfSense CE up to version 2.9.0 contains a CRLF injection vulnerability in the DNS Resolver Access Lists feature. Authenticated users with the DNS Resolver: Access Lists privilege can inject Unbound configuration directives by embedding CR/LF characters in certain fields. This allows modification of DNS behavior for LAN clients by adding directives such as local-data, local-zone, or forward-zone.
CVSS v4.0
Score 5.1medium
Affected software
Netgate
pfSense CE
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-111227 is a CRLF injection vulnerability in Netgate pfSense CE through version 2.9.0, specifically in the services_unbound_acls.php component. Authenticated users with the DNS Resolver: Access Lists privilege can inject carriage return and line feed characters into the aclname or aclaction fields, which are written to access_lists.conf. This injection enables attackers to add Unbound DNS configuration directives like local-data, local-zone, or forward-zone, thereby controlling DNS responses served to LAN clients.
Potential Impact
An attacker with appropriate privileges can manipulate DNS resolver configuration to alter DNS responses for LAN clients. This could lead to DNS spoofing or redirection within the local network. The vulnerability requires authenticated access with specific privileges, limiting the scope of exploitation. The CVSS 4.0 score is 5.1, indicating a medium severity impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, restrict access to the DNS Resolver: Access Lists privilege to trusted administrators only. Monitor for unusual changes in Unbound configuration files and DNS behavior.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-15T18:21:22.605Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad123be2cdf04f65652b748
Added to database: 10/15/2026, 19:04:30 UTC
Last enriched: 10/15/2026, 19:19:14 UTC
Last updated: 10/15/2026, 19:19:21 UTC
Views: 9
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