Weak Key Derivation in openssl_encrypt Affects Cryptographic Security
CVE-2026-74889

9.3CRITICAL

Key Information:

Vendor

Jahlives

Status
OpenSSL Encrypt
Vendor
CVE Published:
17 August 2026

What is CVE-2026-74889?

The openssl_encrypt function prior to version 1.4.0 is vulnerable due to the use of HKDF without salt and static information during key normalization. This setup diminishes entropy extraction and introduces deterministic outcomes that can be exploited. Attackers may leverage this vulnerability, especially in multi-target scenarios, leading to potential breaches in cryptographic security, as identical inputs produce predictable keys that weaken defenses. It is crucial for users to upgrade to the latest version to mitigate these risks.

Affected Version(s)

openssl_encrypt 0 < 1.4.0

openssl_encrypt 1.4.0

References

https://github.com/jahlives/openssl_encrypt/security/advi...
vendor-advisory
https://www.vulncheck.com/advisories/openssl-encrypt-befo...
third-party-advisory

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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