CVE-2026-78594

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

MEDIUM
4.9
CVSS Score
Published: September 2, 2026 at 02:43 PM UTC
Updated: September 3, 2026 at 07:24 PM UTC
1 product affected across 1 vendorAPM Server

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Severity
MEDIUM4.9
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

APM Server· Elasticelastic-plugin
95%
8.0.0 ≤ v ≤ 8.19.198.0.0 ≤ v < 8.19.209.0.0 ≤ v ≤ 9.4.49.0.0 ≤ v < 9.4.58.0.09.0.09.5.0
Affected range stops below 8.19.20, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.4.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.9MEDIUMelastic
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-409

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