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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00086.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
ruby net-imap affected
Version Status Constraints
< 0.4.24 affected —
>= 0.5.0, < 0.5.14 affected —
>= 0.6.0, < 0.6.4 affected —

Configuration 1 [-]

OR cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:*
cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:*
cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:*

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Ruby-lang Subscribe
Net::imap Subscribe

Project Subscriptions

Vendors Products
Ruby-lang Subscribe
Net::imap Subscribe
Net\ Subscribe
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-q2mw-fvj9-vvcw net-imap has quadratic complexity when reading response literals
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca96 cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d34819 cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/releases/tag/v0.4.24 cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/releases/tag/v0.5.14 cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/releases/tag/v0.6.4 cve-icon cve-icon cve-icon
https://github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-42245 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-42245 cve-icon
History

Mon, 18 May 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Ruby-lang net\
CPEs cpe:2.3:a:ruby-lang:net\:\:imap:*:*:*:*:*:ruby:*:*
Vendors & Products Ruby-lang net\
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Sat, 16 May 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-606
References
Metrics threat_severity

None

 cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Tue, 12 May 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Sun, 10 May 2026 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Ruby-lang
Ruby-lang net::imap
Vendors & Products Ruby-lang
Ruby-lang net::imap

Sat, 09 May 2026 20:00:00 +0000

Type Values Removed Values Added
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.
Title net-imap: Quadratic complexity when reading response literals
Weaknesses CWE-407
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-12T18:30:58.415Z

Reserved: 2026-04-25T05:37:12.118Z

Link: CVE-2026-42245

cve-icon Vulnrichment

Updated: 2026-05-12T17:54:00.543Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-09T20:16:28.017

Modified: 2026-05-18T18:12:26.317

Link: CVE-2026-42245

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-09T19:37:08Z

Links: CVE-2026-42245 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-16T02:00:12Z

Weaknesses