CVE-2026-6691

Publication date 6 May 2026

Last updated 13 May 2026


Ubuntu priority

Cvss 3 Severity Score

7.8 · High

Score breakdown

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.

Status

Package Ubuntu Release Status
mongo-c-driver 26.04 LTS resolute
Not affected
25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.8 · High

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


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