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PYSEC-2026-3773

Quick fix

PYSEC-2026-3773 — openssl-encrypt: upgrade to the fixed version with the command below.

pip install --upgrade 'openssl-encrypt>=1.4.0'

Details

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.

Are you affected?

Enter the version of the package you're using.

Affected packages

PyPI/openssl-encrypt

Introduced in: 0Fixed in: 1.4.0

Fixpip install --upgrade 'openssl-encrypt>=1.4.0'

References

https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-w4j7-wfgw-r52w[ADVISORY]
https://www.vulncheck.com/advisories/openssl-encrypt-before-authentication-bypass-via-aes-ctr-fallback[ADVISORY]