CVE-2026-9129Network attack vector

Authenticated file disclosure via encoded absolute paths

Published May 20, 2026 · Updated May 20, 2026

Path traversal in Altium Enterprise Server before 8.0.4 allows remote authenticated users to read arbitrary server files. The Viewer StorageController treats a URL-encoded absolute path in a storage API route as authoritative, discarding the configured storage root instead of constraining the resolved path. The flaw requires a regular account and an on-premise deployment using local filesystem storage; exposed configuration can reveal database credentials, signing-key locations, certificate passwords, and OAuth secrets.

CVSS severity9.4
Critical
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Altium Enterprise Server before 8.0.4 allows remote authenticated users to read arbitrary server files. The Viewer StorageController treats a URL-encoded absolute path in a storage API route as authoritative, discarding the configured storage root instead of constraining the resolved path. The flaw requires a regular account and an on-premise deployment using local filesystem storage; exposed configuration can reveal database credentials, signing-key locations, certificate passwords, and OAuth secrets.

The record

CVE
CVE-2026-9129
Published
May 20, 2026
Updated
May 20, 2026
Vendor
Altium
Product
Altium On-Prem Enterprise Server
Classifications
CWE-22, CWE-200, CAPEC-639, CAPEC-126, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <8.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Altium · Altium On-Prem Enterprise Serverversion=0 <8.0.4

Published CVSS scores

9.4AltiumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CAPEC-639Probe System Files
CAPEC-126Path Traversal
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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