Dashboard / CVE-2026-6691

CVE-2026-6691

HIGH
MEDIUM Priority: 0.01 BB Relevance: 52/100
Published: 2026-05-06 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: None
S: X
AT: None
VC: High
VI: High
VA: High

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.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
mongodb c_driver 2.1.0 – 2.1.2

References & Advisories (1)

https://jira.mongodb.org/browse/CDRIVER-6134
Patch Vendor Advisory Issue Tracking

Bug Bounty Relevance

52 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.6 / 10.0 v4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.13%
Raw Score 0.001260
Percentile 2.3%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00126
2026-10-28
0.00126

Intelligence Sources

nvd ref →

External Links