SB2026081852 - Heap-based buffer overflow in MongoDB driver for C

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Main Vulnerability Database SB2026081852

SB2026081852 - Heap-based buffer overflow in MongoDB driver for C

Published: August 18, 2026

Security Bulletin ID SB2026081852
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Heap-based buffer overflow (CVE-ID: CVE-2026-6691)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in the MongoDB C Driver Cyrus SASL integration when canonicalizing the username from a MongoDB URI with authMechanism=GSSAPI. A remote attacker can supply a specially crafted username value to execute arbitrary code.

User interaction is required to pass untrusted input in the username of a MongoDB URI.


Remediation

Install update from vendor's website.

References