Authentication bypass via issuer-and-serial-only certificate equality
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
The MongoDB C# Driver from 1.8.0 before 3.13.0 compares TLS client certificates by issuer and serial number only when deciding whether clients can share cached connections. In an application that creates clients from certificates supplied by different users, a user presenting a certificate with another user's issuer and serial number, without that user's private key, can receive connections authenticated as the other user. Database operations then run under that identity, affecting the confidentiality and integrity of data it can access. The flaw is classified as CWE-1025.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Description from the CNA
The MongoDB C# Driver compares TLS client certificates by issuer and serial number only when deciding whether two clients can share cached connections. In an application that creates clients from certificates supplied by different users, a user who provides a certificate copying another user's issuer and serial number, without that user's private key, can be given connections authenticated with the other user's certificate. Database operations can then run under the other user's identity, affecting the confidentiality and integrity of data that identity can access.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade the MongoDB C# Driver to version 3.13.0 or later. CVSS 4.0 rates this issue at 7.6 (HIGH) according to the source data.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
- Fix · CNA C# Driver (MongoDB) Fixed in 3.13.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
MongoDB C# Driver 3.13.0
11 records Highest priority Priority HIGH 5 HIGH, 6 MEDIUM
Other records, highest priority first
- TI-2026-79432 BSON output corruption via out-of-range binary subtype in MongoDB C# DriverPriority HIGH 70
- TI-2026-79424 NoSQL command injection via mismatched BSON length in MongoDB C# DriverPriority HIGH 70
- TI-2026-79422 Unbounded memory growth in MongoDB C# Driver BSON deserializationPriority HIGH 69
Timeline
- 2026-10-22 Threatist record created from CVE-2026-114649
- 2026-10-23 1 new reference · CNA
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-11-02 CISA SSVC decision points changed
- 2026-11-02 Priority changed: LOW → HIGH
References
More MongoDB vulnerabilities
- TI-2019-08023 Code injection in mongo-express KEVCVSS 3.1CRITICAL 9.9
- TI-2025-13542 Zlib compressed protocol header length confusion may allow memory read KEVCVSS 4.0HIGH 8.7
- TI-2026-79432 BSON output corruption via out-of-range binary subtype in MongoDB C# Driver CVSS 4.0MEDIUM 6.9
- TI-2026-79424 NoSQL command injection via mismatched BSON length in MongoDB C# Driver CVSS 4.0MEDIUM 6.9
- TI-2026-79422 Unbounded memory growth in MongoDB C# Driver BSON deserialization CVSS 4.0HIGH 8.2
- TI-2026-79426 NoSQL injection in MongoDB C# Driver LINQ filter field names CVSS 4.0HIGH 7.2
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences