CVE-2026-47242 - Medium Severity Vulnerability
Vulnerable Library - net-imap-0.6.4.gem
Ruby client api for Internet Message Access Protocol
Library home page: https://rubygems.org/gems/net-imap-0.6.4.gem
Path to dependency file: /Gemfile.lock
Path to vulnerable library: /tmp/containerbase/cache/.ruby/cache/net-imap-0.6.4.gem
Dependency Hierarchy:
- rails-8.0.5.gem (Root Library)
- actionmailer-8.0.5.gem
- mail-2.9.0.gem
- ❌ net-imap-0.6.4.gem (Vulnerable Library)
Found in base branch: master
Vulnerability Details
Summary Two "Net::IMAP" commands, "#id" and "#enable", do not validate their arguments. Arguments to either command could be used by an attacker to inject arbitrary IMAP commands. Please note that passing untrusted inputs to these commands is usually inappropriate and expected to be uncommon. Details When "Net::IMAP#id" is called with a hash argument, although the ID field value strings are correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF sequences. While "Net::IMAP#enable" does process its arguments for aliases, it does not validate them as valid atoms (or as a list of valid atoms). The "#to_s" value is sent verbatim. Impact This is expected to impact very few users: use of untrusted user input for either command is expected to be very uncommon. The documentation for "#enable" explicitly warns that using any arguments that are not in the explicitly supported list may result in undocumented behavior. Using arbitrary untrusted user input for "#enable" will always be inappropriate. Although client ID field values will most commonly be static and hardcoded, dynamic input sources may be used. For example, client ID fields may be set by configuration or version numbers. Using untrusted user inputs for client ID fields is expected to be uncommon. But any untrusted inputs to client ID can trivially exploit this vulnerability. Untrusted inputs to either command may include a CRLF sequence followed by a new IMAP command (like DELETE mailbox). Although this does not directly enable data exfiltration, it could be combined with other attack vectors or knowledge of the target system's attributes, e.g.: shared mail folders or the application's installed response handlers. Mitigation Update to a version of "net-imap" which validates "#id" and "#enable" arguments. Untrusted inputs should never be used for "#enable" arguments. If "net-imap" cannot be upgraded: * do not use untrusted inputs for client ID field values * or add validation that client ID field values must not contain any CR or LF bytes.
Publish Date: 2026-06-11
URL: CVE-2026-47242
CVSS 3 Score Details (6.1)
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Local
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: Required
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: None
- Integrity Impact: High
- Availability Impact: Low
For more information on CVSS3 Scores, click here.
Suggested Fix
Type: Upgrade version
Release Date: 2026-06-11
Fix Resolution: https://github.com/ruby/net-imap.git - 0.5.15,net-imap - 0.6.4.1,net-imap - 0.5.15
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CVE-2026-47242 - Medium Severity Vulnerability
Ruby client api for Internet Message Access Protocol
Library home page: https://rubygems.org/gems/net-imap-0.6.4.gem
Path to dependency file: /Gemfile.lock
Path to vulnerable library: /tmp/containerbase/cache/.ruby/cache/net-imap-0.6.4.gem
Dependency Hierarchy:
Found in base branch: master
Summary Two "Net::IMAP" commands, "#id" and "#enable", do not validate their arguments. Arguments to either command could be used by an attacker to inject arbitrary IMAP commands. Please note that passing untrusted inputs to these commands is usually inappropriate and expected to be uncommon. Details When "Net::IMAP#id" is called with a hash argument, although the ID field value strings are correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF sequences. While "Net::IMAP#enable" does process its arguments for aliases, it does not validate them as valid atoms (or as a list of valid atoms). The "#to_s" value is sent verbatim. Impact This is expected to impact very few users: use of untrusted user input for either command is expected to be very uncommon. The documentation for "#enable" explicitly warns that using any arguments that are not in the explicitly supported list may result in undocumented behavior. Using arbitrary untrusted user input for "#enable" will always be inappropriate. Although client ID field values will most commonly be static and hardcoded, dynamic input sources may be used. For example, client ID fields may be set by configuration or version numbers. Using untrusted user inputs for client ID fields is expected to be uncommon. But any untrusted inputs to client ID can trivially exploit this vulnerability. Untrusted inputs to either command may include a CRLF sequence followed by a new IMAP command (like DELETE mailbox). Although this does not directly enable data exfiltration, it could be combined with other attack vectors or knowledge of the target system's attributes, e.g.: shared mail folders or the application's installed response handlers. Mitigation Update to a version of "net-imap" which validates "#id" and "#enable" arguments. Untrusted inputs should never be used for "#enable" arguments. If "net-imap" cannot be upgraded: * do not use untrusted inputs for client ID field values * or add validation that client ID field values must not contain any CR or LF bytes.
Publish Date: 2026-06-11
URL: CVE-2026-47242
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Local
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: Required
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: None
- Integrity Impact: High
- Availability Impact: Low
For more information on CVSS3 Scores, click here.Type: Upgrade version
Release Date: 2026-06-11
Fix Resolution: https://github.com/ruby/net-imap.git - 0.5.15,net-imap - 0.6.4.1,net-imap - 0.5.15
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