# CVE-2026-13077: Out-of-Bounds Heap Read in BSON CodeWScope Element Parsing via Malformed BSONColumn Data

CVE-2026-13077 is fixed in MongoDB on 1 platform by MongoDB 8.3.7 (version 8.3.7), released June 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-13077
- Priority: High
- CVSS: 7.1
- EPSS: 0.0042
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 22, 2026
- Weakness: CWE-125: Out-of-bounds Read
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-13077

## Description

A missing bounds check in the BSON CodeWScope element accessors allows an attacker to trigger an out-of-bounds heap read via a crafted aggregation pipeline. The vulnerability can be exploited by an authenticated user by generating a malformed BSONColumn data containing a CodeWScope element, bypassing wire-level BSON validation. When the forged element is decompressed, the unchecked size value is used in pointer arithmetic, causing either a server crash or disclosure of adjacent heap memory contents.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | MongoDB | 8.3.7 | [MongoDB 8.3.7](https://patchblox.com/security/data/fix/windows-app/mongodb.server-8.3.7.md) | Jun 11, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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