{"id":"CVE-2026-74901","summary":"openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback","details":"openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in pqc.py where AES-GCM decryption failures trigger fallback to unauthenticated AES-CTR mode. Attackers can modify ciphertext in transit to bypass integrity verification and perform bit-flipping attacks without detection.","aliases":["GHSA-w4j7-wfgw-r52w"],"modified":"2026-08-19T03:49:00.384663453Z","published":"2026-08-17T11:04:59.916Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-347"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74901.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74901.json"},{"type":"ADVISORY","url":"https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-w4j7-wfgw-r52w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74901"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/openssl-encrypt-before-authentication-bypass-via-aes-ctr-fallback"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/jahlives/openssl_encrypt","events":[{"introduced":"0"},{"fixed":"768df5cd1910e349509f07a27eeac6951e0003bf"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.4.0"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74901.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}