CVE-2026-42256
net-imap: Denial of service via high iteration count for `SCRAM-*` authentication
CVSS Score
0.0
EPSS Score
0.1%
EPSS Percentile
16th
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.
| CWE | CWE-1322 CWE-770 |
| Vendor | ruby |
| Product | net-imap |
| Ecosystems | |
| Industries | Technology |
| Published | May 9, 2026 |
| Last Updated | May 11, 2026 |
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Affected Versions
ruby / net-imap
>= 0.4.0, < 0.4.24 >= 0.5.0, < 0.5.14 >= 0.6.0, < 0.6.4
References
github.com: https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7 github.com: https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612 github.com: https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4 github.com: https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758 github.com: https://github.com/ruby/net-imap/releases/tag/v0.4.24 github.com: https://github.com/ruby/net-imap/releases/tag/v0.5.14 github.com: https://github.com/ruby/net-imap/releases/tag/v0.6.4