CVE-2026-6691

HIGH

7.8

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.

CVE Details

CVSS v3.1 Score7.8

SeverityHIGH

CVSS VectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack VectorLOCAL

ComplexityLOW

Privileges RequiredNONE

User InteractionREQUIRED

Published5/6/2026

Last Modified5/7/2026

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-120

References

https://jira.mongodb.org/browse/CDRIVER-6134(cna@mongodb.com)

IOC Correlations

No correlations recorded

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