{"id":"CVE-2026-59640","state":"PUBLISHED","title":"OpenPGP CFB quick-check oracle active on symmetric/session-key paths","description":"In Bouncy Castle for Java before 1.85, OpenPGP CFB quick-check oracle active on symmetric/session-key paths. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","publishedAt":"2026-08-03T00:55:19.062Z","updatedAt":"2026-08-03T13:25:07.454Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber","source":"bcorg"},"assigner":"bcorg","products":["Legion of the Bouncy Castle Inc. BC-JAVA","Legion of the Bouncy Castle Inc. BC-LTS-JAVA","Legion of the Bouncy Castle Inc. BC-FJA"],"affected":[{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-JAVA","packageName":"bcpg","packageURL":"pkg:maven/org.bouncycastle/bcpg-jdk18on","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.85","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java/","repo":"https://github.com/bcgit/bc-java","modules":["pg"],"programFiles":["PGPEncryptedData","PGPPublicKeyEncryptedData","PGPSessionKeyEncryptedData","PGPSymmetricKeyEncryptedData"]},{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-LTS-JAVA","packageName":"bcpg-lts8on","packageURL":"pkg:maven/org.bouncycastle/bcpg-lts8on","defaultStatus":"unaffected","versions":[{"version":"2.73.0","status":"affected","lessThan":"2.73.12","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java-lts/","repo":"https://github.com/bcgit/bc-lts-java","modules":["pg"],"programFiles":["PGPEncryptedData","PGPPublicKeyEncryptedData","PGPSessionKeyEncryptedData","PGPSymmetricKeyEncryptedData"]},{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-FJA","packageName":"bcpg-fips","packageURL":"pkg:maven/org.bouncycastle/bcpg-fips","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"1.0.13","versionType":"maven"},{"version":"2.0.0","status":"affected","lessThan":"2.0.13","versionType":"maven"},{"version":"2.1.0","status":"affected","lessThan":"2.1.13","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java-fips/"}],"references":["https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059640","https://github.com/bcgit/bc-java/commit/6b94b1c146cec1f565d9a85847fae511af77503e"],"weaknesses":["CWE-203"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59640.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59640","state":"PUBLISHED","datePublished":"2026-08-03T00:55:19.062Z","dateUpdated":"2026-08-03T13:25:07.454Z","assignerShortName":"bcorg","assignerOrgId":"91579145-5d7b-4cc5-b925-a0262ff19630","dateReserved":"2026-07-06T06:58:29.263Z"},"containers":{"cna":{"title":"OpenPGP CFB quick-check oracle active on symmetric/session-key paths","descriptions":[{"lang":"en","value":"In Bouncy Castle for Java before 1.85, OpenPGP CFB quick-check oracle active on symmetric/session-key paths. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series)."}],"affected":[{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-JAVA","packageName":"bcpg","packageURL":"pkg:maven/org.bouncycastle/bcpg-jdk18on","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.85","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java/","repo":"https://github.com/bcgit/bc-java","modules":["pg"],"programFiles":["PGPEncryptedData","PGPPublicKeyEncryptedData","PGPSessionKeyEncryptedData","PGPSymmetricKeyEncryptedData"]},{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-LTS-JAVA","packageName":"bcpg-lts8on","packageURL":"pkg:maven/org.bouncycastle/bcpg-lts8on","defaultStatus":"unaffected","versions":[{"version":"2.73.0","status":"affected","lessThan":"2.73.12","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java-lts/","repo":"https://github.com/bcgit/bc-lts-java","modules":["pg"],"programFiles":["PGPEncryptedData","PGPPublicKeyEncryptedData","PGPSessionKeyEncryptedData","PGPSymmetricKeyEncryptedData"]},{"vendor":"Legion of the Bouncy Castle Inc.","product":"BC-FJA","packageName":"bcpg-fips","packageURL":"pkg:maven/org.bouncycastle/bcpg-fips","defaultStatus":"unaffected","versions":[{"version":"1.0.0","status":"affected","lessThan":"1.0.13","versionType":"maven"},{"version":"2.0.0","status":"affected","lessThan":"2.0.13","versionType":"maven"},{"version":"2.1.0","status":"affected","lessThan":"2.1.13","versionType":"maven"}],"platforms":["all"],"collectionURL":"https://www.bouncycastle.org/download/bouncy-castle-java-fips/"}],"references":[{"url":"https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059640","tags":["vendor-advisory"]},{"url":"https://github.com/bcgit/bc-java/commit/6b94b1c146cec1f565d9a85847fae511af77503e","tags":["patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"AMBER","version":"4.0","baseSeverity":"HIGH","baseScore":8.7,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/U:Amber"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-203","lang":"en","description":"CWE-203 Observable Discrepancy","type":"CWE"}]}],"providerMetadata":{"shortName":"bcorg","orgId":"91579145-5d7b-4cc5-b925-a0262ff19630","dateUpdated":"2026-08-03T05:04:51.696Z"},"credits":[{"lang":"en","value":"Alex Gaynor in collaboration with Claude and Anthropic Research","type":"reporter"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"bc release-notes template"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-03T13:24:55.789890Z","id":"CVE-2026-59640","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-03T13:25:07.454Z"}}]}}}