What is CVE-2026-87732?

CVE-2026-87732 is a medium-severity vulnerability in Ocaml Mirage-Crypto, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.2/10. Published 2026-09-09.

How severe is CVE-2026-87732?

Medium severity. CVSS v3 base score is 6.2 out of 10.

Vulnerability in Ocaml Mirage-Crypto

CVE-2026-87732

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.

CVSS v3 metric

CVSS v3 base score 6.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Ocaml Mirage-crypto

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

cve@mitre.org

Frequently asked questions

What is CVE-2026-87732?: CVE-2026-87732 is a medium-severity vulnerability in Ocaml Mirage-Crypto, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.2/10. Published 2026-09-09.
How severe is CVE-2026-87732?: Medium severity. CVSS v3 base score is 6.2 out of 10.