CVE-2026-88035

Heap buffer overflow via wrapped size check during SASL username canonicalization in MongoDB C Driver

Published Sep 10, 2026 CVSS 4.0 · 5.7 Medium EPSS < 1% KEV · Not listed
Description
A size check in the client-side authentication path of the MongoDB C Driver can wrap around, so an unusually large user-name value is accepted and copied past the end of a small buffer. A party able to set the driver's connection settings may cause the application that embeds the driver to terminate unexpectedly. Reaching this code requires a build in which the optional external SASL authentication backend is present and a connection configured to use it.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*
Type Values Removed Values Added
First Time appeared Mongodb
Mongodb c Driver
Vendors & Products Mongodb
Mongodb c Driver
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description A size check in the client-side authentication path of the MongoDB C Driver can wrap around, so an unusually large user-name value is accepted and copied past the end of a small buffer. A party able to set the driver's connection settings may cause the application that embeds the driver to terminate unexpectedly. Reaching this code requires a build in which the optional external SASL authentication backend is present and a connection configured to use it.
Title Heap buffer overflow via wrapped size check during SASL username canonicalization in MongoDB C Driver
Weaknesses CWE-190
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 5.7, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mongodb
Published
Updated
Sep 10, 2026, 6:29 PM
Reserved
Sep 9, 2026, 7:49 PM
Status
Analyzed
Published
Sep 10, 2026, 7:17 PM
Modified
Sep 16, 2026, 6:08 PM