SB2026050487 - Multiple vulnerabilities in MongoDB

Description

This security bulletin contains information about 2 vulnerabilities.

1) Integer underflow (CVE-ID: CVE-2026-6914)

CWE-ID: CWE-191 - Integer underflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to integer underflow in binDataClean() when computing the MD5 checksum of a malformed BSON object. A remote attacker can supply a malformed BSON object to cause a denial of service.

2) Missing Authorization (CVE-ID: CVE-2026-6915)

CWE-ID: CWE-862 - Missing Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to weaken another user's authentication configuration.

The vulnerability exists due to improper access control in the updateUser command when processing user update requests. A remote user can submit a crafted updateUser command to weaken another user's authentication configuration.

The issue allows downgrading any other user's authentication mechanism from SCRAM-SHA-256 to SCRAM-SHA-1.

Remediation

Install update from vendor's website.

References

• https://jira.mongodb.org/browse/SERVER-119981
• https://jira.mongodb.org/browse/SERVER-119679
• https://github.com/10gen/mongo/blob/master/src/mongo/db/commands/user_management_commands_common.cpp#L219