Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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ReconAuthenticate to APM Server with write-privileged account
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DeliveryCraft highly compressed zip-bomb source map payload
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ExploitUpload payload via source map API
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InstallAPM Server decompresses payload on processing
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C2Heap memory exhausted
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ExecuteServer process terminates
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ImpactCondition recurs on every restart
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V2 - Validation and Business Logic Compression ratio limits
|
| Exploitation Conditions | Exploitation requires an authenticated account with write (ingest) access to APM Server's source map content endpoint - a high-privilege role (PR:H per CVSS). No special network positioning is required; the attack is executed over the standard APM Server HTTP/S API (AV:N, AC:L). The vulnerability is limited to the source map processing path specifically: generic APM event ingestion does not trigger this code. There is no user interaction required from other users or administrators to trigger the crash - the server processes stored source maps autonomously. The persistent recurrence is bounded only by whether an administrator can locate and remove the malicious content before the next restart cycle. |
| Impact | The CVSS 3.1 score of 4.9 (Medium) accurately reflects the high-privilege prerequisite (PR:H), which substantially limits the attack surface to users with explicit write access to the source map API - not the general authenticated user population. Despite the moderate score, the persistence mechanic is the defining risk amplifier: unlike a transient DoS, this vulnerability puts the APM Server into an unrecoverable crash loop that requires administrative intervention on disk, not just a restart. Even a mid-sized municipal IT team in inowroclaw running Elastic APM for infrastructure observability would face a complete APM visibility blackout until the malicious source map is identified and removed. No KEV listing and no public exploit code are confirmed at time of analysis, keeping real-world exploitation probability low absent an insider or compromised privileged account. EPSS data was not provided in the input; given PR:H and no KEV, opportunistic mass exploitation is unlikely. |
| Exploit ScenarioDerived | An attacker with a privileged APM Server account - or an insider with source map upload rights - crafts a polyglot zip-bomb payload compressed to a few kilobytes that decompresses to tens of gigabytes, then uploads it via the source map API. On the next source map processing cycle, APM Server attempts full decompression, exhausts all available heap, and the process is terminated by the OS OOM killer. Every subsequent restart re-triggers the same processing path and the same crash, rendering APM monitoring permanently unavailable until an administrator manually purges the stored artifact. |
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Alert meAnalysisAIv1 – Sep 02, 2026
Persistent denial of service in Elastic APM Server allows an authenticated user with write access to source map content to upload specially crafted, highly compressed payloads that exhaust server memory upon processing. The condition (CWE-409, CAPEC-130) is self-reinforcing: every restart triggers re-processing of the stored content and re-crashes the server, making recovery impossible without manual removal of the malicious content. No public exploit code has been identified and the vulnerability is not listed in CISA KEV; however, the persistence characteristic significantly elevates operational impact compared to a transient DoS.
RemediationAI
Upgrade APM Server to a patched release per ESA-2026-152: inferred fixed versions from the advisory URL are 8.19.20 (8.x branch), 9.4.5 (9.4.x branch), and 9.5.1 (9.5.x branch) - confirm exact versions at https://discuss.elastic.co/t/apm-server-8-19-20-9-4-5-9-5-1-security-update-esa-2026-152/390110 before upgrading. If an immediate upgrade is not possible, restrict write access to the source map API endpoint to the minimum set of trusted accounts and monitor for unexpectedly large compressed payloads. If the server is already in a crash loop, identify and delete the offending source map artifact directly from the backing data store before restarting. Restricting the APM Server process memory limit via OS-level controls (e.g., ulimit or cgroup memory limits) can bound the blast radius but will not prevent the crash - it only constrains collateral damage to co-located processes.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
APM Server (cpe:2.3:a:elastic:apm_server:*:*:*:*:*:*:*:*) is Elastic's backend component that receives, processes, and forwards application performance monitoring data, including JavaScript source maps used to decode minified stack traces. CWE-409 describes a failure to impose limits on decompression expansion ratios - the classic 'zip bomb' pattern covered by CAPEC-130 (Excessive Allocation). When APM Server decompresses a source map submitted by an authenticated user, it allocates memory proportional to the uncompressed output size without a bound check, allowing a tiny compressed payload to expand to gigabytes and exhaust the heap. The affected CPE covers all versions of the server-side APM application within the Elastic stack.
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Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Write access to source maps requires high privilege (PR:H); persistent availability destruction justifies A:H; no confidentiality or integrity impact.
Primary rating from Vendor (elastic).
CVSS VectorVendor: elastic
DescriptionCVE.org
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.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
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EUVD-2026-70058
GHSA-5jf2-hccc-p8fm
NVD
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EPSS
Vulnrichment
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Exploit-DB