PatchSiren cyber security CVE debrief

CVE-2026-11431 Altium CVE debrief

A path traversal vulnerability exists in the Projects Service download endpoint shared by Altium Enterprise Server and Altium 365. An authenticated user can supply a crafted path parameter that bypasses validation, allowing arbitrary files (including entire directories returned as archives) to be read from the server filesystem. Because the readable files include service configuration and credential material, exploitation can be used to gather information enabling further compromise. The issue can be combined with CVE-2026-11424 to reach the cloud-side endpoint. On multi-tenant Altium 365 deployments, the readable configuration could have exposed credentials shared across services. Altium Enterprise Server is fixed in 8.1.1; the issue has been remediated in Altium 365 at the service level.

Vendor: Altium
Product: Altium Enterprise Server
CVSS: HIGH 8.3
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-05
Original CVE updated: 2026-07-23
Advisory published: 2026-06-05
Advisory updated: 2026-07-23

Who should care

Users of Altium Enterprise Server and Altium 365 should apply the provided patches to prevent exploitation of this vulnerability.

Technical summary

The vulnerability has a CVSS score of 8.3 and is classified as HIGH severity. It can be exploited by an authenticated user with a crafted path parameter, allowing access to sensitive files and configuration data.

Defensive priority

High

Recommended defensive actions

Apply the patch for Altium Enterprise Server version 8.1.1
Ensure that Altium 365 has been updated to the latest service level

Evidence notes

Vendor: Altium; Product: Altium Enterprise Server and Altium 365

Sources and references

Verified primary and authoritative sources

CVE-2026-11431 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-11431

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-11431 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-11431

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Source reference
Unverified legacy reference

URL: https://www.altium.com/platform/security-compliance/security-advisories

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Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.