{"id":"USN-8478-1","summary":"ruby2.7, ruby3.0, ruby3.2, ruby3.3 vulnerabilities","details":"It was discovered that Ruby's Net::IMAP library did not properly verify\nthat TLS encryption was started after issuing a STARTTLS command. A remote\nattacker could use this to perform a machine-in-the-middle attack and silently\nbypass TLS encryption. (CVE-2026-42246)\n\nIt was discovered that Ruby's Net::IMAP library did not validate\nstring arguments passed to certain commands. A remote attacker could use\nthis to inject arbitrary IMAP commands. (CVE-2026-42257)\n\nIt was discovered that Ruby's Net::IMAP library was vulnerable to a\ndenial of service attack when authenticating with SCRAM-SHA1 or\nSCRAM-SHA256. A hostile server could send a very large iteration count\nvalue to cause excessive computation in the client. This issue only\naffected ruby3.3. (CVE-2026-42256)","modified":"2026-06-30T18:17:38.194035123Z","published":"2025-06-29T09:15:31Z","related":["UBUNTU-CVE-2026-42246","UBUNTU-CVE-2026-42256","UBUNTU-CVE-2026-42257"],"upstream":["UBUNTU-CVE-2026-42246","UBUNTU-CVE-2026-42256","UBUNTU-CVE-2026-42257"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8478-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42246"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42256"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42257"}],"affected":[{"package":{"name":"ruby2.7","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/ruby2.7?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.7.0-5ubuntu1.18+esm5"}]}],"versions":["2.7.0-1","2.7.0-2","2.7.0-3","2.7.0-4","2.7.0-4ubuntu1","2.7.0-5ubuntu1","2.7.0-5ubuntu1.1","2.7.0-5ubuntu1.2","2.7.0-5ubuntu1.3","2.7.0-5ubuntu1.4","2.7.0-5ubuntu1.5","2.7.0-5ubuntu1.6","2.7.0-5ubuntu1.7","2.7.0-5ubuntu1.8","2.7.0-5ubuntu1.9","2.7.0-5ubuntu1.10","2.7.0-5ubuntu1.11","2.7.0-5ubuntu1.12","2.7.0-5ubuntu1.13","2.7.0-5ubuntu1.14","2.7.0-5ubuntu1.15","2.7.0-5ubuntu1.16","2.7.0-5ubuntu1.17","2.7.0-5ubuntu1.18","2.7.0-5ubuntu1.18+esm1","2.7.0-5ubuntu1.18+esm3","2.7.0-5ubuntu1.18+esm4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"2.7.0-5ubuntu1.18+esm5","binary_name":"libruby2.7"},{"binary_version":"2.7.0-5ubuntu1.18+esm5","binary_name":"ruby2.7"}]},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2026-42246","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]},{"id":"CVE-2026-42257","severity":[{"score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:Pro:20.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8478-1.json"}},{"package":{"name":"ruby3.0","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ruby3.0?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.2-7ubuntu2.13"}]}],"versions":["3.0.2-5ubuntu1","3.0.2-7","3.0.2-7ubuntu2","3.0.2-7ubuntu2.1","3.0.2-7ubuntu2.2","3.0.2-7ubuntu2.3","3.0.2-7ubuntu2.4","3.0.2-7ubuntu2.5","3.0.2-7ubuntu2.6","3.0.2-7ubuntu2.7","3.0.2-7ubuntu2.8","3.0.2-7ubuntu2.10","3.0.2-7ubuntu2.11","3.0.2-7ubuntu2.12"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"3.0.2-7ubuntu2.13","binary_name":"libruby3.0"},{"binary_name":"ruby3.0","binary_version":"3.0.2-7ubuntu2.13"}]},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2026-42246","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]},{"id":"CVE-2026-42257","severity":[{"score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:22.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8478-1.json"}},{"package":{"name":"ruby3.2","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ruby3.2?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.3-1ubuntu0.24.04.8"}]}],"versions":["3.2.3-1","3.2.3-1build2","3.2.3-1build3","3.2.3-1ubuntu0.24.04.1","3.2.3-1ubuntu0.24.04.3","3.2.3-1ubuntu0.24.04.5","3.2.3-1ubuntu0.24.04.6","3.2.3-1ubuntu0.24.04.7"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"3.2.3-1ubuntu0.24.04.8","binary_name":"libruby3.2"},{"binary_version":"3.2.3-1ubuntu0.24.04.8","binary_name":"ruby3.2"}]},"database_specific":{"cves_map":{"cves":[{"id":"CVE-2026-42246","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]},{"id":"CVE-2026-42257","severity":[{"score":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","type":"CVSS_V4"},{"score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","type":"CVSS_V3"},{"score":"medium","type":"Ubuntu"}]}],"ecosystem":"Ubuntu:24.04:LTS"},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8478-1.json"}},{"package":{"name":"ruby3.3","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/ruby3.3?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.8-2ubuntu3.1"}]}],"versions":["3.3.8-2ubuntu2","3.3.8-2ubuntu3"],"ecosystem_specific":{"availability":"No 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