CVE-2026-74900

openssl_encrypt versions before 1.4.0 contain a critical vulnerability in pqc.py where KEM decapsulation failures silently fall back to simulation mode, generating a deterministic shared secret from only 16 bytes of the private key and publicly available encapsulated key data. Attackers who obtain 16 bytes of the private key can compute the shared secret and decrypt all ciphertext, as the fallback triggers on any KEM failure without raising an error.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-p3gq-pcg9-qvfv	Mitigation Vendor Advisory
https://www.vulncheck.com/advisories/openssl-encrypt-before-weak-shared-secret-via-pqc-simulation-mode	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:jahlives:openssl_encrypt:*:*:*:*:*:python:*:*

History

No history.

Information

Published : 2026-08-17 11:16

Updated : 2026-09-01 15:24

NVD link : CVE-2026-74900

Mitre link : CVE-2026-74900

CVE.ORG link : CVE-2026-74900

JSON object : View

Products Affected

jahlives

openssl_encrypt

CWE

CWE-391

Unchecked Error Condition

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