{"id":"CVE-2026-103601","revision":"93c82f4f54094919a2a51630bca67c59","records":[{"revision":"93c82f4f54094919a2a51630bca67c59","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-103601","aliases":[],"title":"CcmBlockCipher and KCcmBlockCipher leave unverified plaintext in the output buffer after a failed tag check","description":"Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an application that lets the output buffer of a failed decryption be observed, for example through buffer reuse or logging, because decryption wrote the recovered plaintext into the caller-supplied output buffer before checking the authentication tag and left it there when the check failed. Only decryption into a caller-supplied buffer is affected; methods that return a newly allocated array are not.","state":0,"publishedAt":"2026-10-02T07:09:17.064+00:00","modifiedAt":"2026-10-02T17:52:45.9+00:00","affected":[{"ecosystem":"https://www.nuget.org/packages/BouncyCastle.Cryptography","name":"BouncyCastle.Cryptography","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Legion of the Bouncy Castle Inc.\",\n                    \"product\": \"bc-csharp\",\n                    \"collectionURL\": \"https://www.nuget.org/packages/BouncyCastle.Cryptography\",\n                    \"packageName\": \"BouncyCastle.Cryptography\",\n                    \"repo\": \"https://github.com/bcgit/bc-csharp\",\n                    \"programFiles\": [\n                        \"crypto/src/crypto/modes/CcmBlockCipher.cs\",\n                        \"crypto/src/crypto/modes/KCcmBlockCipher.cs\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.7.0\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":8.2,"severity":"HIGH"}],"references":["https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103601","https://github.com/bcgit/bc-csharp/commit/e0868323645a063cb2479646e93c1449dc338de5","https://github.com/bcgit/bc-csharp/commit/4ddb1d0bfeae3a81b18f4446d8cc8a7871bd2d9f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-103601","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-103601","identifiers":["CVE-2026-103601"]},"retained":false,"historicalAffected":[]}],"coverage":[]}