{"id":"CVE-2026-74901","aliases":["EUVD-2026-60118","GHSA-jw8h-gwjw-g7rc","GHSA-w4j7-wfgw-r52w","PYSEC-2026-3773"],"status":"published","title":"openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback","description":"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.","severity":{"version":"4.0","score":9.3,"vector":"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","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00405,"percentile":0.35168,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-347"],"published":"2026-08-17T11:04:59Z","modified":"2026-10-28T02:31:15Z","fixes":[{"ecosystem":"PyPI","package":"openssl-encrypt","fixed_in":["1.4.0"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"PyPI","package":"openssl-encrypt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.0"}]}],"versions":["0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.3.0","0.3.1","0.3.2","0.3.3","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.5.0","0.5.1","0.5.3","0.6.0rc1","0.7.0rc2","0.7.1","0.7.2","0.8.0","0.8.1","0.8.2","0.9.2","1.0.0","1.0.1","1.0.2","1.0.3","1.1.0","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.4.0b3","1.4.0b4","1.4.0b5","1.4.0b6","1.4.0b7","1.4.0b8"]}],"products":[{"vendor":"jahlives","product":"openssl_encrypt"}],"references":[{"url":"https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-w4j7-wfgw-r52w","tags":["vendor-advisory","Mitigation","Vendor Advisory","advisory"]},{"url":"https://www.vulncheck.com/advisories/openssl-encrypt-before-authentication-bypass-via-aes-ctr-fallback","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74901","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-jw8h-gwjw-g7rc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74901.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-74901","title":"openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback","description":"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.","status":"published","published":"2026-08-17T11:04:59.916Z","modified":"2026-10-01T15:21:06.55Z","cvss":[{"version":"4.0","score":9.3,"vector":"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","level":"critical","assessor":"cna"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:20:03.081354Z"}],"euvd":[{"id":"EUVD-2026-60118","description":"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.","status":"published","published":"2026-08-17T11:04:59Z","modified":"2026-10-01T15:21:06Z","cvss":[{"version":"4.0","score":9.3,"vector":"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","level":"critical"}],"updated_at":"2026-11-02T17:27:45.017929Z"}],"ghsa":[{"id":"GHSA-jw8h-gwjw-g7rc","title":"openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in pqc.py...","description":"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.","status":"published","published":"2026-08-17T12:32:27Z","modified":"2026-08-17T12:32:27Z","cvss":[{"version":"4.0","score":9.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:10:34.0369Z"}],"nvd":[{"id":"CVE-2026-74901","description":"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.","status":"published","published":"2026-08-17T11:16:45.183Z","modified":"2026-09-01T16:08:27.007Z","cvss":[{"version":"4.0","score":9.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:12:38.647684Z"}],"osv":[{"id":"CVE-2026-74901","title":"openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback","description":"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.","status":"published","published":"2026-08-17T11:04:59.916Z","modified":"2026-10-28T02:31:15.059795204Z","cvss":[{"version":"4.0","score":9.3,"vector":"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","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:45:16.748692Z"},{"id":"PYSEC-2026-3773","description":"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.","status":"published","published":"2026-08-17T11:16:45.183Z","modified":"2026-09-02T09:00:04.182657535Z","cvss":[{"version":"4.0","score":9.3,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"updated_at":"2026-11-02T15:52:57.255153Z"}]}}