CVE-2026-93394: MongoDB C Driver · Incorrect Implementation of Authentication Algorithm
Affects MongoDB C DriverSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium : upgrade to 2.3.2 when convenient.
Data as of 1 Nov 2026, 22:58 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.3.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
Upgrade MongoDB C Driver to 2.3.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MongoDB Inc.C Driver | Affected
| Fixed in
|
AI-suggested
Use TLS to protect authentication traffic, as this vulnerability is mitigated by TLS, which is standard in production deployments. Upgrade MongoDB C Driver to version 2.3.2 or later where this issue is fixed. Patch status is confirmed by the affectedVersions field indicating versions <2.3.2 are vulnerable, implying 2.3.2 contains the fix.
Description
CVE-2026-93394 is a vulnerability in MongoDB Inc.'s C Driver (libmongoc) affecting versions from 2.0.0 up to but not including 2.3.2. The flaw lies in the SCRAM authentication implementation, where the client proceeds with the authentication handshake and sends the client proof even if a nonce mismatch is detected in the server's first message. This could allow a man-in-the-middle attacker to inject a crafted server message and capture the client proof, potentially enabling offline password cracking. The vulnerability is mitigated by the use of TLS, which is standard in production environments.