Improper Handling of Highly Compressed Data in APM Server Leading to Persistent Denial of Service (CVE-2026-78594) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-78594

Improper Handling of Highly Compressed Data in APM Server Leading to Persistent Denial of Service

Answer in brief

CVE-2026-78594 records a Unknown severity vulnerability in Improper Handling of Highly Compressed Data in APM Server Leading to Persistent Denial of Service. The current sources do not mark it as known exploited. The current feed maps Elastic/Apm Server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 2, 2026Updated Sep 2, 2026Source checked Sep 2, 2026First seen by HOL Sep 2, 2026Material review Sep 2, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Elastic/Apm Server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Elastic/Apm Servergeneric	8.0.0 \|\| 9.0.0 \|\| 9.5.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Elastic/Apm Server.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 2, 2026

Sources and claim methodology

Source referencediscuss.elastic.co

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.