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TI-2026-59887 Aliases CVE-2026-87732GHSA-vqxm-cgmv-2pcr

Improper signature verification in OCaml mirage-crypto

Priority MEDIUM 61CWE-347Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-347.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00107 1st percentileScored 2026-11-07
Fix Fixed mirage-crypto (OCaml): 2.2.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OCamlmirage-cryptobefore 2.2.02.2.0Patch availableCNA
  • mirage-crypto VendorOCaml Affected before 2.2.0 Fixed in 2.2.0 Patch available CNA

Remediation

  • Fix · CNA mirage-crypto (OCaml) Fixed in 2.2.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-87732
  2. 2026-10-03 Alias added: GHSA-vqxm-cgmv-2pcr

References

Other 1

  • TI-2026-60369 Improper signature verification in OCaml jose CVSS 3.1CRITICAL 9.1
  • TI-2026-59889 An issue was discovered in the utcp package before 0.0.6 for OCaml. CVSS 3.1HIGH 7.5
  • TI-2026-29719 In OCaml opam before 2.5.1, a .install field containing a destination filepath can use ../ to reach a parent directory. CVSS 3.1HIGH 7.8
  • TI-2026-59888 Improper certificate validation in OCaml mirage-crypto-ec CVSS 3.1MEDIUM 6.2
  • TI-2018-07003 The caml_ba_deserialize function in byterun/bigarray.c in the standard library in OCaml… CVSS 3.0CRITICAL 9.8
  • TI-2017-07154 Insufficient sanitisation in the OCaml compiler versions 4.04.0 and 4.04.1 allows… CVSS 3.0CRITICAL 9.8
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences