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TI-2026-62967 Aliases CVE-2026-93394GHSA-cxv8-vf43-xcw5

libmongoc SCRAM client nonce-validation bypass

Priority LOW 28CWE-303Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00321 25th percentileScored 2026-11-07
Fix Fixed C Driver (MongoDB Inc.): 2.3.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
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
MongoDBC Driver2.0.0 to before 2.3.22.3.2Patch availableCNA
  • C Driver VendorMongoDB Affected 2.0.0 to before 2.3.2 Fixed in 2.3.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*2.0.0 to before 2.3.2VulnerableMongoDB
  • cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:* Versions 2.0.0 to before 2.3.2 Vulnerable ·MongoDB

Remediation

  • Fix · CNA C Driver (MongoDB Inc.) Fixed in 2.3.2

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-93394
  2. 2026-10-03 Alias added: GHSA-cxv8-vf43-xcw5
  3. 2026-11-06 Affected versions changed · Red Hat
  4. 2026-11-06 CVSS score added · Red Hat

References

Other 1

  • TI-2026-62966 Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream CVSS 4.0CRITICAL 9.2
  • TI-2026-05870 MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow CVSS 4.0HIGH 8.6
  • TI-2026-62968 Integer Underflow → Heap Out-of-Bounds Read in `bson_new_from_buffer() CVSS 4.0MEDIUM 6.9
  • TI-2024-07001 Accessing Untrusted Directory May Allow Local Privilege Escalation CVSS 3.1HIGH 7.8
  • TI-2026-58387 Heap corruption via OCSP request double free from crafted multi-URL certificate in TLS client CVSS 4.0HIGH 8.2
  • TI-2023-00414 MongoDB client C Driver may infinitely loop when validating certain BSON input data CVSS 3.1HIGH 7.5
See all 20 →

Sources

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