CVE-2026-93394libmongoc SCRAM client nonce-validation bypass
Updated under an hour ago ()
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It affects MongoDB Inc. C Driver. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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A flaw in libmongoc's SCRAM authentication implementation caused the client to continue the authentication handshake and transmit the client proof even when a nonce mismatch was detected in the server's first message. An unauthorized party with a man-in-the-middle position could exploit this by injecting a crafted server-first-message containing a controlled salt and low iteration count, then capturing the resulting client proof to perform offline password cracking. This vulnerability is mitigated by TLS, which is standard in production deployments.
- CVSS
- 3.7 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- Weakness (CWE)
- CWE-303
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mongodb
- NVD analysis
- Analyzed
- Record last updated
- Sep 18, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
MongoDB Inc. C Driver mongodb:c_driver (from the name) | from 2.0.0 before 2.3.2 | CNA record |
mongodb c_driver mongodb:c_driver | from 2.0.0 before 2.3.2 | NVD |
References
- https://jira.mongodb.org/browse/CDRIVER-6315permissions-required
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.