# CVE-2026-78594: Improper Handling of Highly Compressed Data in APM Server Leading to Persistent Denial of Service

> CVE-2026-78594: Improper Handling of Highly Compressed Data in APM Server Leading to Persistent Denial of Service. CVSS 4.9 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-78594
Last updated: 2026-09-03T19:13:49Z

- Published: 2026-09-02 14:43 UTC · Updated: 2026-09-03 19:13 UTC · Assigner: elastic
- CVSS: 4.9 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.50%, 43th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-409

## Description

Improper Handling of Highly Compressed Data (CWE-409) in APM Server can lead to a persistent denial of service via Excessive Allocation (CAPEC-130). An authenticated user with write access to source map content could store specially crafted, highly compressed content that exhausts the memory available to APM Server when it is later processed, terminating the process. The condition recurs on every restart until the stored content is removed.

## Affected vendors and products

- Elastic: Apm Server

## Tracked companies

- [Elastic Cloud](https://rewindex.com/company/elastic-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-78594)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-78594)
- [https://discuss.elastic.co/t/apm-server-8-19-20-9-4-5-9-5-1-security-update-esa-2026-152/390110](https://discuss.elastic.co/t/apm-server-8-19-20-9-4-5-9-5-1-security-update-esa-2026-152/390110)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-78594 · Markdown: https://rewindex.com/cve/CVE-2026-78594.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-78594 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:59.897Z