# CVE-2026-87732

## Summary

- **CVE ID:** CVE-2026-87732
- **Severity:** MEDIUM
- **CVSS Score:** 6.2 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
- **CWE:** CWE-347
- **Published:** Sep 9, 2026
- **Last Modified:** Sep 9, 2026

## Description

An issue was discovered in the mirage-crypto package before 2.2.0 for OCaml. The AES.GCM.authenticate_decrypt_into and Chacha20.authenticate_decrypt_into functions write the decrypted plaintext into a caller-provided buffer and only then compares the tag. On a forged tag, the functions returns false, but the destination buffer already holds the full plaintext.

## Affected Products

- OCaml — mirage-crypto (0)

## References

- [CNA](https://osv.dev/vulnerability/OSEC-2026-12)

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._