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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-42256 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 6.0 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612 GitHub, Inc. Patch 
https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4 GitHub, Inc. Patch 
https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758 GitHub, Inc. Patch 
https://github.com/ruby/net-imap/releases/tag/v0.4.24 GitHub, Inc. Release Notes 
https://github.com/ruby/net-imap/releases/tag/v0.5.14 GitHub, Inc. Release Notes 
https://github.com/ruby/net-imap/releases/tag/v0.6.4 GitHub, Inc. Release Notes 
https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7 GitHub, Inc. Mitigation  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-770 Allocation of Resources Without Limits or Throttling GitHub, Inc.  
CWE-1322 Use of Blocking Code in Single-threaded, Non-blocking Context GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

5 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-42256
NVD Published Date:
05/09/2026
NVD Last Modified:
07/24/2026
Source:
GitHub, Inc.