Altium Enterprise Server: Improper Limitation of a Pathname to a Restricted Directory
CVE-2026-11414 is a critical-severity improper limitation of a pathname to a restricted directory vulnerability in Altium Enterprise Server from Altium, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 8.1.1 as the first without the flaw, so updating Altium Enterprise Server to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Altium Enterprise Server to 8.1.1 or a later version.
- Update On-prem Enterprise Server to 8.1.1 or a later version.
- Read the advisory on altium.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Altium | Altium Enterprise Server | before 8.1.1 | 8.1.1 |
| Altium | On-prem Enterprise Server | before 8.1.1 | 8.1.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 10.0 | Critical | CNA |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
A hard-coded cryptographic key is used by Altium Enterprise Server to sign file download URLs in the Vault service. Because the key is identical across all installations, an unauthenticated network attacker who can reach the server can forge valid download signatures and retrieve files from the Vault storage area without any authentication, session, or credentials. A separate path traversal vulnerability in the same download endpoint allows the configured storage root to be escaped, enabling reads of arbitrary files on the server filesystem. Combined, these issues allow an unauthenticated attacker to obtain sensitive server configuration and key material, which can lead to full server compromise. The vulnerability can be chained with CVE-2026-9152 to enumerate and bulk-download stored content. Altium 365 cloud deployments are not impacted in practice, as file storage uses object storage rather than the local filesystem.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Altium Enterprise Server
- 10.0 Critical severity
- 9.4 Critical severity
- 8.3 High severity
- 10.0 Critical severity
- 8.3 High severity
- 9.4 Critical severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 8.1 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
- 8.8 High severity
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