{"id":"CVE-2026-59638","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-59638","summary":"JSSE hostname verifier CN-fallback enabled by default despite documented opt-in","details":"In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).","published":"2026-08-03T00:57:31.904Z","modified":"2026-09-04T11:45:58.868695739Z","cvss":null,"epss":{"score":0.00292,"percentile":0.21141,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[],"fix":{"url":"https://github.com/bcgit/bc-java/commit/5ac55351cd1a8a7184d41c96a7ee87df0770240a","label":"bcgit/bc-java@5ac5535"},"references":[{"type":"WEB","url":"https://www.bouncycastle.org/download/bouncy-castle-java-fips/"},{"type":"WEB","url":"https://www.bouncycastle.org/download/bouncy-castle-java-lts/"},{"type":"WEB","url":"https://www.bouncycastle.org/download/bouncy-castle-java/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59638.json"},{"type":"ADVISORY","url":"https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059638"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59638"},{"type":"FIX","url":"https://github.com/bcgit/bc-java/commit/5ac55351cd1a8a7184d41c96a7ee87df0770240a"},{"type":"FIX","url":"https://github.com/bcgit/bc-java/commit/799bd15320a6310a447863638aa3df64acef829b"},{"type":"PACKAGE","url":"https://github.com/bcgit/bc-java"},{"type":"PACKAGE","url":"https://github.com/bcgit/bc-lts-java"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-04T11:45:58.868695739Z"}}