CVE-2026-9753 (CVSS 8.1)

Description

The $_internalApplyOplogUpdate aggregation pipeline stage can be used to execute a document diff containing a malformed binary diff to return memory out-of-bounds or crash the server. $_internalApplyOplogUpdate can be executed by any authenticated user with access to the aggregate command.

Is your site exposed to CVE-2026-9753?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.1

HIGH

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

EPSS — Exploit Prediction

0.0030

Probability of exploitation

0.22%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-1287 CWE-1287

References

Other References

https://jira.mongodb.org/browse/SERVER-124959

Frequently Asked Questions

What is CVE-2026-9753? +

The $_internalApplyOplogUpdate aggregation pipeline stage can be used to execute a document diff containing a malformed binary diff to return memory out-of-bounds or crash the server. $_internalApplyOplogUpdate can be executed by any authenticated user with access to the aggregate command. It has a CVSS v3.1 base score of 8.1 (HIGH).

How severe is CVE-2026-9753? +

CVE-2026-9753 has a CVSS v3.1 score of 8.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0030, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-9753? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-61672

Synapse is an open source Matrix homeserver implementation. Lack of validation for device keys in Synapse before 1.138.3 and in …

CVE-2025-9041

A security issue exists due to improper handling of CIP Class 32’s request when a module is inhibited on the …

CVE-2026-80051

github.com/graphql-go/graphql (GraphQL for Go) through 0.8.1 does not validate that a scalar variable value matches its declared type. The built-in …

CVE-2025-9042

A security issue exists due to improper handling of CIP Class 32’s request when a module is inhibited on the …

CVE-2026-10825

A denial-of-service vulnerability exists in the WebSocket API due to insufficient validation and handling of JSON-based requests. A low-privileged authenticated …

CVE-2026-82741

Improper Validation of Specified Type of Input vulnerability in ash-project ash lets an attacker confuse the stored type tag of …

CVE-2026-9753