Description
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.
Published: 2026-08-17
Score: 9.3 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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History

Fri, 21 Aug 2026 13:00:00 +0000

Type Values Removed Values Added
First Time appeared Jahlives
Jahlives openssl Encrypt
Vendors & Products Jahlives
Jahlives openssl Encrypt

Mon, 17 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 17 Aug 2026 11:15:00 +0000

Type Values Removed Values Added
Description 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.
Title openssl_encrypt before 1.4.0 Weak Shared Secret via PQC Simulation Mode
Weaknesses CWE-391
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Jahlives Openssl Encrypt
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-17T12:47:06.168Z

Reserved: 2026-08-17T10:48:45.738Z

Link: CVE-2026-74900

cve-icon Vulnrichment

Updated: 2026-08-17T12:47:00.700Z

cve-icon NVD

Status : Received

Published: 2026-08-17T11:16:45.050

Modified: 2026-08-17T13:16:53.973

Link: CVE-2026-74900

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T12:40:27Z

Weaknesses