IMAP command injection via unvalidated raw arguments
Published May 9, 2026 · Updated May 9, 2026
Command injection in Ruby net-imap allows attackers to modify or delete IMAP data through crafted raw command arguments. Affected command paths convert selected String values to Net::IMAP::RawData, bypass validation and write embedded CRLF bytes directly to the socket. A consuming application must pass attacker-controlled input into a raw argument; injected commands run under its authenticated IMAP session.
Summary
What happened
Command injection in Ruby net-imap allows attackers to modify or delete IMAP data through crafted raw command arguments. Affected command paths convert selected String values to Net::IMAP::RawData, bypass validation and write embedded CRLF bytes directly to the socket. A consuming application must pass attacker-controlled input into a raw argument; injected commands run under its authenticated IMAP session.
The record
- CVE
- CVE-2026-42257
- Published
- May 9, 2026
- Updated
- May 9, 2026
- Vendor
- libwww-perl
- Product
- net-imap
- Classifications
- CWE-93, CWE-77
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 9, 2026CVE publishedPublication date reported by the CVE source.
- May 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 0.4.24
- Affected versionversion=>= 0.5.0, < 0.5.14
- Affected versionversion=>= 0.6.0, < 0.6.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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