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.
Published: 2026-05-06
Score: 8.6 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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History

Thu, 07 May 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb c Driver
Vendors & Products Mongodb
Mongodb c Driver

Wed, 06 May 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 06 May 2026 15:30:00 +0000

Type Values Removed Values Added
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.
Title MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow
Weaknesses CWE-120
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, 'vector': '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'}


Subscriptions

Mongodb C Driver
cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-05-07T03:55:47.410Z

Reserved: 2026-04-20T16:17:41.724Z

Link: CVE-2026-6691

cve-icon Vulnrichment

Updated: 2026-05-06T15:24:26.254Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-06T16:16:11.483

Modified: 2026-05-07T15:11:09.037

Link: CVE-2026-6691

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-07T21:25:38Z

Weaknesses