CVE-2026-42256

MEDIUM EPSS 21.5%
Published May 9, 20261mo ago · Modified Jun 17, 20262w ago
6.0 CVSS 4.0
Medium
Find Similar
Published May 9, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
6.0
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
21.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-1322
CWE-770

Affected Products 3

VendorProductVersionRange
ruby-langnet\\≥0.4.0  –  <0.4.24
ruby-langnet\\≥0.5.0  –  <0.5.14
ruby-langnet\\≥0.6.0  –  <0.6.4

References 7

  • github.com https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612
    Patch
  • github.com https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4
    Patch
  • github.com https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758
    Patch
  • github.com https://github.com/ruby/net-imap/releases/tag/v0.4.24
    Release Notes
  • github.com https://github.com/ruby/net-imap/releases/tag/v0.5.14
    Release Notes
  • github.com https://github.com/ruby/net-imap/releases/tag/v0.6.4
    Release Notes
  • github.com https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7
    MitigationVendor Advisory

Remediation

  • github.com https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612
    Patch
  • github.com https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4
    Patch
  • github.com https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758
    Patch