openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.
History

Thu, 27 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Description openssl_encrypt versions before 1.4.9 store an unkeyed SHA-256 hash of the plaintext in the cleartext file header metadata. Attackers can read this hash without the password to confirm guessed plaintexts offline or fingerprint identical plaintexts across separately-encrypted files.
Title openssl_encrypt before 1.4.9 Plaintext Confirmation Oracle via SHA-256
Weaknesses CWE-311
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-27T18:20:12.907Z

Reserved: 2026-08-27T11:12:00.889Z

Link: CVE-2026-81688

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-27T17:20:58.553

Modified: 2026-08-27T17:20:58.553

Link: CVE-2026-81688

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.