# CVE-2026-120820: Uncontrolled Resource Consumption in MongoDB Server Per-Namespace Encrypted-Field Statistics Table Leads to Denial of Service

Status: published. Published: 2026-11-10. Updated: 2026-11-13.

MongoDB Server maintains an in-memory table of per-namespace statistics for operations that carry encrypted-field information. Entries are created for any namespace supplied in a request, with no limit on the number of entries and no way to remove entries that never corresponded to a real collection. A user with basic read privileges who repeatedly issues ordinary read commands referencing arbitrary namespace names may cause the server process to retain steadily increasing amounts of memory and to slow down on the affected code path; the memory is reclaimed only by restarting the process.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- MongoDB / MongoDB Server: ≥ 9.0.0; < 9.0.7 (affected, semver); ≥ 8.3.0; < 8.3.16 (affected, semver); ≥ 8.0.0; < 8.0.37 (affected, semver). Source: CNA: mongodb

## Severity and prioritization

- CVSS 4.0: 5.3 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: mongodb

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L; source: CNA: mongodb

- CVSS 4.0: 5.3 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: cna@mongodb.com

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L; source: NVD: cna@mongodb.com

- CISA KEV: No listing in collected sources

- EPSS: 0.36% as of 2026-11-13; percentile 30.03%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-770

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://jira.mongodb.org/browse/SERVER-135737 (CNA: mongodb)

- https://jira.mongodb.org/browse/SERVER-135737 (cna@mongodb.com)

## Provenance

- CNA: mongodb: https://www.cve.org/CVERecord?id=CVE-2026-120820; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-120820; retrieved 2026-11-11; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-120820; retrieved 2026-11-13; source updated Not reported

Revision: e94f8448a629cc276caadc3325123aef18bae2a0cb7dc160828374bbb7991ee0

Canonical: https://y2.dev/cve/CVE-2026-120820

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