{"id":"CVE-2020-8897","aliases":["GHSA-wqgp-vphw-hphf","PYSEC-2020-261"],"url":"https://o3.security/vulnerability/CVE-2020-8897","summary":"Security issues in AWS KMS and AWS Encryption SDKs: in-band protocol negotiation and robustness","details":"A weak robustness vulnerability exists in the AWS Encryption SDKs for Java, Python, C and Javalcript prior to versions 2.0.0. Due to the non-committing property of AES-GCM (and other AEAD ciphers such as AES-GCM-SIV or (X)ChaCha20Poly1305) used by the SDKs to encrypt messages, an attacker can craft a unique cyphertext which will decrypt to multiple different results, and becomes especially relevant in a multi-recipient setting. We recommend users update their SDK to 2.0.0 or later.","published":"2020-11-16T12:15:14.557Z","modified":"2026-07-09T01:06:58.484112Z","cvss":{"score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"},"epss":{"score":0.00399,"percentile":0.33324,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Maven","name":"com.amazonaws:aws-encryption-sdk-java","fixedVersion":"2.0.0"},{"ecosystem":"PyPI","name":"aws-encryption-sdk","fixedVersion":"2.0.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://aws.amazon.com/blogs/security/improved-client-side-encryption-explicit-keyids-and-key-commitment/"},{"type":"EVIDENCE","url":"https://github.com/google/security-research/security/advisories/GHSA-wqgp-vphw-hphf"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T01:06:58.484112Z"}}