CVE-2026-42256

CVE Details

Release Date:	2026-05-09
Impact:	Moderate	What is this?

Description

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. From versions 0.4.0 to before 0.4.24, 0.5.0 to before 0.5.14, and 0.6.0 to before 0.6.4, when authenticating a connection with SCRAM-SHA1 or SCRAM-SHA256, a hostile server can perform a computational denial-of-service attack on the client process by sending a big iteration count value. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

See more information about CVE-2026-42256 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	6.5
Vector String:	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	None
User Interaction:	Required
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (ruby)	ELSA-2026-50728	2026-08-10
Oracle Linux version 8 (rubygem-abrt)	ELSA-2026-50728	2026-08-10
Oracle Linux version 8 (rubygem-mysql2)	ELSA-2026-50728	2026-08-10
Oracle Linux version 8 (rubygem-pg)	ELSA-2026-50728	2026-08-10
Oracle Linux version 9 (ruby)	ELSA-2026-50827	2026-08-10
Oracle Linux version 9 (ruby)	ELSA-2026-50828	2026-08-07
Oracle Linux version 9 (rubygem-mysql2)	ELSA-2026-50827	2026-08-10
Oracle Linux version 9 (rubygem-mysql2)	ELSA-2026-50828	2026-08-07
Oracle Linux version 9 (rubygem-pg)	ELSA-2026-50827	2026-08-10
Oracle Linux version 9 (rubygem-pg)	ELSA-2026-50828	2026-08-07