CVE-2026-6691
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.
- Affected products
- Red Os, Mongodb C Driver
- Mongodb C Driver
- < 2.1.2
- CVSS 4.0
- 8.6 HIGH
- CVSS 3.1
- 7.8 HIGH
- EPSS
- 0.1% (3th percentile)
- Weakness
- CWE-120, CWE-787
- NVD status
- Analyzed
- Published
- 2026-05-06
- Attack patterns
- CAPEC-100
CVE-2026-6691 at NVD
No indexed exploits for CVE-2026-6691 yet
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No exploit for CVE-2026-6691 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.