CVE-2026-74889 jahlives CVE debrief

Who should care

Developers and administrators using openssl_encrypt for cryptographic operations should be aware of this vulnerability and take action to upgrade to a secure version. Additionally, security teams and auditors evaluating cryptographic security should consider the potential impact of this vulnerability on multi-target attacks.

Technical summary

The openssl_encrypt library, prior to version 1.4.0, utilizes HKDF with no salt and a static info parameter in its key normalization functions. This implementation reduces entropy extraction and determinism, potentially allowing attackers to exploit predictable key derivation with identical inputs. Such predictability could weaken cryptographic security against multi-target attacks. Users of openssl_encrypt are advised to upgrade to version 1.4.0 or later to address this vulnerability.

Defensive priority

openssl_encrypt users should prioritize upgrading to version 1.4.0 or later to address the weak key derivation issue.

Recommended defensive actions

• Upgrade to openssl_encrypt version 1.4.0 or later
• Review and update cryptographic configurations to ensure proper entropy extraction
• Monitor for potential multi-target attacks against weakened cryptographic security
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE description notes that openssl_encrypt versions before 1.4.0 use HKDF with no salt and static info parameter in key normalization functions, reducing entropy extraction and determinism. This could allow attackers to exploit predictable key derivation with identical inputs to weaken cryptographic security against multi-target attacks. However, detailed impact analysis and affected scope remain limited based on provided source data.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.