openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback
Published Aug 17, 2026 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
openssl_encrypt versions before 1.4.0 contain an authentication bypass vulnerability in pqc.py where AES-GCM decryption failures trigger fallback to unauthenticated AES-CTR mode. Attackers can modify ciphertext in transit to bypass integrity verification and perform bit-flipping attacks without detection.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
- Security advisory ↗
- VulnCheck Advisory: openssl_encrypt before 1.4.0 Authentication Bypass via AES-CTR Fallback ↗
Record history
Published Aug 17, 2026 · Last refreshed Nov 3, 2026