Buffer Overflow Vulnerability in Mirage-Crypto Package for OCaml

CVE-2026-87732

What is CVE-2026-87732?

A vulnerability exists in the mirage-crypto package prior to version 2.2.0 for OCaml that may allow an attacker to expose sensitive information. The functions AES.GCM.authenticate_decrypt_into and Chacha20.authenticate_decrypt_into handle decryption processes but possess a flaw in which the decrypted plaintext is written to a provided buffer before the integrity of the cryptographic tag is verified. If the tag is forged, the functions will inaccurately return false, yet the buffer will still contain the full, decrypted plaintext, potentially enabling unauthorized access to sensitive data.

References