{"id":"CVE-2026-74901","aliases":["PYSEC-2026-3773","GHSA-w4j7-wfgw-r52w"],"title":"openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in pqc.py where AES-GCM decryption failures trigger …","summary":"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 integ…","severity":"none","vendor":"openssl-encrypt","product":"openssl-encrypt","ecosystem":"pip","affected":["openssl-encrypt < 1.4.0"],"patched":["openssl-encrypt 1.4.0"],"published":"2026-08-17","updated":"2026-09-02","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/PYSEC-2026-3773","references":[{"url":"https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-w4j7-wfgw-r52w"},{"url":"https://www.vulncheck.com/advisories/openssl-encrypt-before-authentication-bypass-via-aes-ctr-fallback"}],"tags":["osv","pip"],"epss":0.00228,"epssPercentile":0.13853,"ingestedAt":"2026-09-02T19:31:25.950Z","slug":"CVE-2026-74901","body":"## Overview\n\nopenssl_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.\n\n## Affected packages\n\n- `openssl-encrypt < 1.4.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `openssl-encrypt 1.4.0`","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}