{"id":"CVE-2026-42256","summary":"net-imap: Denial of service via high iteration count for `SCRAM-*` authentication","details":"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.","aliases":["GHSA-87pf-fpwv-p7m7"],"modified":"2026-07-08T08:13:14.012282061Z","published":"2026-05-09T19:38:33.106Z","related":["CGA-7vjj-g7cx-4vwp","openSUSE-SU-2026:21225-1"],"database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42256.json","cwe_ids":["CWE-1322","CWE-770"]},"references":[{"type":"WEB","url":"https://github.com/ruby/net-imap/releases/tag/v0.4.24"},{"type":"WEB","url":"https://github.com/ruby/net-imap/releases/tag/v0.5.14"},{"type":"WEB","url":"https://github.com/ruby/net-imap/releases/tag/v0.6.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42256.json"},{"type":"ADVISORY","url":"https://github.com/ruby/net-imap/security/advisories/GHSA-87pf-fpwv-p7m7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42256"},{"type":"FIX","url":"https://github.com/ruby/net-imap/commit/158d0b505074397cdb5ceb58935e42dd2bcfa612"},{"type":"FIX","url":"https://github.com/ruby/net-imap/commit/808001bc45c06f7297a7e96d341279e041a7f7f4"},{"type":"FIX","url":"https://github.com/ruby/net-imap/commit/99f59eab6064955a23debd95410263ad144df758"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/ruby/net-imap","events":[{"introduced":"a9459de2c725563d27943e73a92a61f69ef9b048"},{"fixed":"24a4e770b43230286a05aa2a9746cdbb3eb8485e"},{"introduced":"cc13c91c65b78ee33ebf4960d547173e761cafdc"},{"fixed":"4063bc1d1d3e21046544ed7a2c131e5f886bab01"},{"introduced":"567518cae5500f7c4776a1fd4e9bbd599e98b9bf"},{"fixed":"3e490673dca65d0cfeeeb3fbf1fdaa188d6f27c4"},{"fixed":"158d0b505074397cdb5ceb58935e42dd2bcfa612"},{"fixed":"808001bc45c06f7297a7e96d341279e041a7f7f4"},{"fixed":"99f59eab6064955a23debd95410263ad144df758"}],"database_specific":{"extracted_events":[{"introduced":"0.4.0"},{"fixed":"0.4.24"},{"introduced":"0.5.0"},{"fixed":"0.5.14"},{"introduced":"0.6.0"},{"fixed":"0.6.4"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:ruby-lang:net\\:\\:imap:*:*:*:*:*:ruby:*:*"}}],"versions":["v0.4.23","v0.5.13","v0.6.2","v0.4.22","v0.6.0","v0.5.12","v0.5.11","v0.5.10","v0.5.9","v0.4.21","v0.5.8","v0.4.20","v0.5.7","v0.4.19","v0.5.6","v0.4.18","v0.5.5","v0.5.4","v0.5.3","v0.5.2","v0.5.1","v0.4.17","v0.5.0","v0.4.16","v0.4.15","v0.4.14","v0.4.13","v0.4.12","v0.4.11","v0.4.10","v0.4.9","v0.4.8","v0.4.7","v0.4.6","v0.4.5","v0.4.4","v0.4.3","v0.4.2","v0.4.1","v0.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42256.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}