CVE-2026-42256CWE-1322CWE-770

net-imap: Denial of service via high iteration count for `SCRAM-*` authentication

Medium · published May 9, 2026

CVSS v4.0
6.0
EPSS
0%
Percentile
22.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
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
EPSS
0.00299 · 22.1th percentile
Weaknesses
CWE-1322 · Use of Blocking Code in Single-threaded, Non-blocking Context; CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-05-09T19:38Z
EPSS history
Timeline
  • 09 MAY 19:38Z
    net-imap: Denial of service via high iteration count for `SCRAM-*` authentication
    cvelistv5