CVE-2026-93394
Description
A flaw was found in libmongoc's SCRAM authentication implementation. This flaw allows an unauthorized attacker in a man-in-the-middle position to bypass nonce validation by injecting a crafted server message. This enables the attacker to capture the client proof and perform offline password cracking. The vulnerability is mitigated by Transport Layer Security (TLS), which is commonly used in production deployments.
Statement
This vulnerability is rated as Moderate severity because exploitation requires an active man-in-the-middle network position on an unencrypted connection and only yields cryptographic proof material that requires offline brute-force cracking rather than direct system compromise. In typical Red Hat deployments, communication with MongoDB servers is protected by TLS encryption, neutralizing the ability of an adversary to inspect or manipulate authentication handshakes. Applications connecting over unencrypted channels or untrusted networks remain susceptible to credential proof extraction if an attacker can alter the network traffic.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
An incorrect implementation may allow authentication to be bypassed.
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