{"id":"CVE-2026-103601","title":"Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc","summary":"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 …","severity":"high","cvss":8.2,"cvssVector":"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","cwe":["CWE-354"],"vendor":"Legion of the Bouncy Castle Inc.","product":"BouncyCastle.Cryptography","affected":["BouncyCastle.Cryptography < 2.7.0"],"published":"2026-10-02","updated":"2026-10-02","sourceUpdated":"2026-10-02T08:17:00.527","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103601","references":[{"url":"https://github.com/bcgit/bc-csharp/commit/4ddb1d0bfeae3a81b18f4446d8cc8a7871bd2d9f","label":"91579145-5d7b-4cc5-b925-a0262ff19630"},{"url":"https://github.com/bcgit/bc-csharp/commit/e0868323645a063cb2479646e93c1449dc338de5","label":"91579145-5d7b-4cc5-b925-a0262ff19630"},{"url":"https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103601","label":"91579145-5d7b-4cc5-b925-a0262ff19630"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-10-02T08:14:06.226Z","slug":"CVE-2026-103601","body":"## Overview\n\nRelease 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":45.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}