CVE-2026-42245: CWE-407: Inefficient Algorithmic Complexity in ruby net-imap
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
AI Analysis
Technical Summary
The Ruby net-imap library's ResponseReader class had an inefficient algorithmic complexity (quadratic time) when reading large IMAP responses with many string literals. This flaw allows a malicious IMAP server to craft responses that cause the client to consume excessive CPU resources, leading to denial of service. The vulnerability affects net-imap versions before 0.4.24, 0.5.14, and 0.6.4. Fixed versions 0.4.24, 0.5.14, and 0.6.4 have resolved this inefficiency.
Potential Impact
A hostile IMAP server can exploit this vulnerability to cause the client application using net-imap to experience high CPU usage, potentially leading to denial of service conditions. There is no indication of data compromise or privilege escalation. The impact is limited to resource exhaustion on the client side.
Mitigation Recommendations
Upgrade net-imap to version 0.4.24, 0.5.14, or 0.6.4 or later, where this vulnerability has been patched. Patch status is confirmed by the version fixes noted in the advisory. No other mitigation is indicated.
CVE-2026-42245: CWE-407: Inefficient Algorithmic Complexity in ruby net-imap
Description
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
CVSS v4.0
Score 2.3low
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Ruby net-imap library's ResponseReader class had an inefficient algorithmic complexity (quadratic time) when reading large IMAP responses with many string literals. This flaw allows a malicious IMAP server to craft responses that cause the client to consume excessive CPU resources, leading to denial of service. The vulnerability affects net-imap versions before 0.4.24, 0.5.14, and 0.6.4. Fixed versions 0.4.24, 0.5.14, and 0.6.4 have resolved this inefficiency.
Potential Impact
A hostile IMAP server can exploit this vulnerability to cause the client application using net-imap to experience high CPU usage, potentially leading to denial of service conditions. There is no indication of data compromise or privilege escalation. The impact is limited to resource exhaustion on the client side.
Mitigation Recommendations
Upgrade net-imap to version 0.4.24, 0.5.14, or 0.6.4 or later, where this vulnerability has been patched. Patch status is confirmed by the version fixes noted in the advisory. No other mitigation is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-25T05:37:12.118Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69ff93c0cbff5d86106e4579
Added to database: 05/09/2026, 20:06:24 UTC
Last enriched: 05/17/2026, 09:54:40 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 113
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