Double Free in MongoDB
CVE-2026-4358
A specially crafted aggregation query with $lookup by an authenticated user with write privileges can cause a double-free or use-after-free memory issue in the slot-based execution (SBE) engine when an in-memory hash table is spilled to disk.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H.
EPSS exploit prediction
EPSS: 0.004 (27.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000
Affected products
- MongoDB
- MongoDB Inc Server — versions 8.2, 8.0, 7.0
Weakness classification (CWE)
References
- jira.mongodb.org/browse/SERVER-118849 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-4358?
- CVE-2026-4358 is a medium-severity vulnerability in MongoDB, classified under Double Free. CVSS score: 6.4/10. Published 2026-03-17.
- How severe is CVE-2026-4358?
- Medium severity. CVSS v3 base score is 6.4 out of 10.