Unauthenticated SOAP Endpoint in Altium 365 SearchService Allows Cross-Tenant Data Exfiltration and Index Destruction

published 2026-05-21 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-31205

cvss: 10.0; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits: 0; none known

A missing authentication vulnerability exists in the Altium 365 SearchService. A legacy SOAP endpoint exposes search index operations without requiring authentication, session tokens, or any form of identity verification. An unauthenticated network attacker who can reference a target workspace's identifier can interact with that workspace's search index, crossing tenant boundaries.

Successful exploitation allows reading a workspace's indexed contents (such as component data, project and folder names, and user metadata) and injecting, modifying, or deleting search index entries. These operations affect the search index only, not the underlying vault data, but they can disclose sensitive workspace information and compromise the integrity and availability of search results. Altium 365 cloud deployments are affected; on-premise Altium Enterprise Server is not affected.

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 5 mo ago (2026-05-21)

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	10.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA	4.0	10.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Altium Altium 365

Classification

Weakness

CWE-306 Missing Authentication for Critical Functionality
CWE-639 Authorization Bypass Through User-Controlled Key

References

altium.com /platform/security-compliance/security-advisories

Sources

CVE List CVE-2026-9152
NVD CVE-2026-9152

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Summary