{"id":"CVE-2026-74871","title":"openssl_encrypt versions before 1.4.6 contain a key derivation flaw in sequential XOR composition mode where the last stage cancels out during key generation","summary":"openssl_encrypt versions before 1.4.6 contain a key derivation flaw in sequential XOR composition mode where the last stage cancels out during key generation. When configured with a single KDF and no prior hashing stage, attackers can by…","severity":"medium","cvss":6.2,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-916"],"vendor":"jahlives","product":"openssl_encrypt","affected":["openssl_encrypt < 1.4.6"],"patched":["openssl_encrypt 1.4.6"],"published":"2026-08-17","updated":"2026-09-10","sourceUpdated":"2026-09-10T16:56:31.877","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74871","references":[{"url":"https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-vxf9-vwp6-2w43","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/openssl-encrypt-before-kdf-bypass-via-sequential-xor","label":"disclosure@vulncheck.com"}],"tags":["nvd","osv","pip"],"epss":0.00081,"epssPercentile":0.00243,"ingestedAt":"2026-09-08T21:11:12.279Z","aliases":["PYSEC-2026-3976","GHSA-vxf9-vwp6-2w43"],"ecosystem":"pip","scores":{"nvd":6.2,"osv":5.5},"slug":"CVE-2026-74871","body":"## Overview\n\nopenssl_encrypt versions before 1.4.6 contain a key derivation flaw in sequential XOR composition mode where the last stage cancels out during key generation. When configured with a single KDF and no prior hashing stage, attackers can bypass memory-hard key derivation and perform offline password cracking at SHA-256 speed instead of the configured KDF cost.\n\n## Affected\n\n- `openssl_encrypt < 1.4.6`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `openssl_encrypt 1.4.6`\n\n## Package advisory (CVE-2026-74871)\n\nAffected packages:\n\n- `openssl-encrypt < 1.4.6`\n\nPatched in:\n\n- `openssl-encrypt 1.4.6`\n\nSource: https://osv.dev/vulnerability/PYSEC-2026-3976","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":34.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}