CVE-2026-9129
CVE-2026-9129 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.
Key facts
- Severity: Critical (CVSS 4.0 base score 9.4)
- EPSS exploit prediction: 0% (15th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-31148
- Weakness: CWE-22
- Published:
- Last modified:
Description
A path traversal vulnerability exists in the Altium Enterprise Server Viewer StorageController due to improper handling of file path route parameters. On on-premise deployments that use local filesystem storage, a regular authenticated user can supply a URL-encoded absolute path (such as an encoded drive letter) in a Viewer storage API request, causing the configured storage root to be discarded and allowing arbitrary files to be read from the server filesystem. Because the readable files include the server's master configuration, which stores database credentials, signing key locations, certificate passwords, and OAuth secrets, exploitation can lead to disclosure of all server secrets and full compromise of the server and its data. Cloud deployments are not affected, as they use object storage and do not enable this component.
Frequently asked questions
- What is CVE-2026-9129?
- A path traversal vulnerability exists in the Altium Enterprise Server Viewer StorageController due to improper handling of file path route parameters. On on-premise deployments that use local filesystem storage, a regular authenticated user can supply a URL-encoded absolute path (such as an encoded drive letter) in a Viewer storage API request, causing the configured storage root to be discarded and allowing arbitrary files to be read from the server filesystem. Because the readable files include the server's master configuration, which stores database credentials, signing key locations, certificate passwords, and OAuth secrets, exploitation can lead to disclosure of all server secrets and full compromise of the server and its data. Cloud deployments are not affected, as they use object storage and do not enable this component.
- How severe is CVE-2026-9129?
- CVE-2026-9129 has a CVSS 4.0 base score of 9.4, rated critical severity.
- Is CVE-2026-9129 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-9129?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-9129 have an EU (EUVD) identifier?
- Yes. CVE-2026-9129 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31148.
- When was CVE-2026-9129 published?
- CVE-2026-9129 was published on 2026-05-20 and last updated on 2026-06-17.
References
Other CWE-22 (Path Traversal) vulnerabilities
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