Ciphertext Comparison Flaw in WolfSSL's ML-KEM for ARM64 Architecture
CVE-2026-6330

6.3MEDIUM

Key Information:

Vendor

Wolfssl

Status
Wolfssl
Vendor
CVE Published:
25 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-6330?

A vulnerability in the ML-KEM implementation for ARM64 architecture in wolfSSL is related to improper ciphertext comparison during the encryption process. Specifically, the comparison method only examines half of the re-encrypted ciphertext, which undermines the effective security measures mandated by the Fujisaki-Okamoto transform. As a result, a malicious actor could manipulate the ciphertext undetected, allowing them to bypass the necessary implicit rejection protocols established for IND-CCA2 security, potentially jeopardizing data integrity and confidentiality.

Affected Version(s)

wolfSSL 5.7.4 <= 5.9.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

ml-kem-key-recovery
Created by 007bsd

References

https://github.com/wolfSSL/wolfssl/pull/10192
patch
https://www.wolfssl.com/docs/security-vulnerabilities/

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Nicholas Carlini from Anthropic
.