CVE-2026-42245
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.7%
51.1th percentile
CISA KEV
Not listed
Weakness / dates
CWE-407
Published 2026-05-09 · modified 2026-07-24
Description
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
Affected
References
- https://github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca96
- https://github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda
- https://github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d34819
- https://github.com/ruby/net-imap/releases/tag/v0.4.24
- https://github.com/ruby/net-imap/releases/tag/v0.5.14
- https://github.com/ruby/net-imap/releases/tag/v0.6.4
- https://github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw