CVE-2026-6691
MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow
- State
- Published
- Severity
- 8.6 High
- Published
- May 6, 2026
- Updated
- May 7, 2026
- Reserved
- Apr 20, 2026
Description
The MongoDB C Driver's Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any authentication or network traffic. This may be triggered by passing untrusted input in the username of a MongoDB URI with authMechanism=GSSAPI.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.6 High | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | mongodb |
| 3.1 | 7.8 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | mongodb |
Weaknesses
- CWE-120 Buffer Copy without Checking Size of Input
Affected Products
| Product | Versions |
|---|---|
MongoDB C DriverMongoDB Inc. |
|
References
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