Fluid Attacks Database

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.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Package	Affected version	Patched versions
rubygems	net-imap	>=0.6.0 <0.6.4 \|\| >=0.5.0 <0.5.14 \|\| >=0 <0.4.24	0.6.4, 0.5.14, 0.4.24
debian 12	ruby3.1	=3.1.2-7 \|\| =3.1.2-7+deb12u1 \|\| =3.1.2-7+hurd.1 \|\| =3.1.2-8 \|\| =3.1.2-8.1~exp1 \|\| =3.1.2-8.3 \|\| =3.1.2-8.4 \|\| =3.1.2-8.5	-
debian 13	ruby3.3	=3.3.8-2 \|\| =3.3.8-2.1 \|\| =3.3.8-2.2	-
debian 14	ruby3.3	=3.3.8-2 \|\| =3.3.8-2.1 \|\| =3.3.8-2.2	-
debian 11	ruby2.7	=2.7.4-1 \|\| =2.7.4-1+deb11u1 \|\| =2.7.4-1+deb11u2 \|\| =2.7.4-1+deb11u3 \|\| =2.7.4-1+deb11u4 \|\| =2.7.4-1+deb11u5 \|\| =2.7.5-1	-
rpm rhel10	ruby4.0	-	-
rpm rhel8	ruby	-	-
rpm rhel9	ruby	-	-
rpm rhel10	ruby	-	-

Aliases

1. CVE-2026-422452. NVD-2026-422453. OSV-2026-422454. OSV-DEBIAN-2026-422455. GHSA-q2mw-fvj9-vvcw6. GCVE-2026-422457. SECURITY-TRACKER-CVE-2026-42245

References

1. https://github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw2. https://github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca963. https://github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda4. https://github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d348195. https://github.com/ruby/net-imap/releases/tag/v0.4.246. https://github.com/ruby/net-imap/releases/tag/v0.5.147. https://github.com/ruby/net-imap/releases/tag/v0.6.48. https://github.com/rubysec/ruby-advisory-db/blob/master/gems/net-imap/CVE-2026-42245.yml

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