What is CVE-2026-6811?

CVE-2026-6811 is a medium-severity vulnerability in MongoDB PHP Driver, classified under Uncontrolled Recursion. CVSS score: 5.9/10. Published 2026-05-14.

How severe is CVE-2026-6811?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in MongoDB PHP Driver

CVE-2026-6811

Stack exhaustion vulnerability in the MongoDB PHP driver can cause application crashes when processing deeply nested BSON documents in unusual circumstances when the source of these BSON documents is not MongoDB Server.

Published 2026-05-14 · last modified 2026-09-24.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (28.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

MongoDB PHP Driver
MongoDB Inc. PHP Driver — versions 1.21.5, 2.1.8

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

jira.mongodb.org/browse/PHPC-2636 (Vendor Advisory)

Frequently asked questions

What is CVE-2026-6811?: CVE-2026-6811 is a medium-severity vulnerability in MongoDB PHP Driver, classified under Uncontrolled Recursion. CVSS score: 5.9/10. Published 2026-05-14.
How severe is CVE-2026-6811?: Medium severity. CVSS v3 base score is 5.9 out of 10.