# CVE-2026-18711: Use-After-Free in MongoDB Query Execution Engine Leads to Denial of Service and Potential Memory Disclosure CVE-2026-18711 is fixed in MongoDB on 1 platform by MongoDB 8.3.11 (version 8.3.11), released September 9, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-18711 - Priority: High - CVSS: 7.1 - EPSS: 0.0049 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 11, 2026 - Weakness: CWE-416: Use After Free - Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-18711 ## Description An issue in MongoDB Server's query execution engine could allow an authenticated user with read and write privileges to cause an internal reference to be used after the underlying memory has been freed, when running certain queries against time-series collections. This could result in a server crash or disclosure of freed memory contents within query results. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Windows apps | MongoDB | 8.3.11 | [MongoDB 8.3.11](https://patchblox.com/security/data/fix/windows-app/mongodb.server-8.3.11.md) | Sep 9, 2026 | --- Data as of 2026-11-09T07:25:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.