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NVD / CVE Program· CNA Altium

CVE-2026-11423: Path Traversal in Altium Enterprise Server Collaboration Service Allows Privilege Escalation

CriticalCVSS 9.4 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 37/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.32% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Altium Altium Enterprise Server 8.1.1.

Low priority for now. Upgrade to Altium Altium Enterprise Server 8.1.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A path traversal vulnerability exists in the Altium Enterprise Server Collaboration Service due to improper handling of user-supplied filenames in the MCAD and Simulation file download flows. A regular authenticated user can submit a collaboration message containing a crafted filename, which is later used to construct the download path on the server without validation, allowing arbitrary files to be read from the server filesystem. Because the readable files include the server's master configuration, which stores credentials for privileged accounts, exploitation can lead to authenticating as a system administrator and gaining full control of the server. Altium 365 cloud deployments are not affected.

Published
Jun 5, 2026
Updated
Jul 23, 2026
EPSS
0.3% · 25th percentile

Report tools

JSON

Action score

37

Monitor

Low priority for now.

CVSS
37 / 40 · 9.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Altium
9.4
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-11423

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Altium). Independent of NVD's CPE analysis and usually ahead of it.

  • Altium Altium Enterprise Server

    • before 8.1.1affected · semver

Same product

altium: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-92808Server-Side Request Forgery in Altium Enterprise Server UnifiedLogin Service Allows Unauthenticated System Compromise
    40Plan
  • CVE-2026-11429Path Traversal in Altium Vault ScriptsController Allows Unauthenticated Remote Code Execution
    40Plan
  • CVE-2026-14439Path Traversal in Altium Git Service Allows Remote Code Execution
    37Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-9102May 20, 2026 · Path Traversal in Altium Enterprise Server ComparisonService Allows Arbitrary File Write
    37Monitor
  • ← EarlierCVE-2026-9129May 20, 2026 · Path Traversal in Altium Enterprise Server Viewer StorageController Allows Arbitrary File Read
    37Monitor
  • Later →CVE-2026-11424Jun 5, 2026 · Server-Side Request Forgery in Altium Platform Design GraphQL Service Allows Information Disclosure
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Altium Altium Enterprise Server8.1.1Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-114290 days apartPath Traversal in Altium Vault ScriptsController Allows Unauthenticated Remote Code Execution
    40Plan
  • CVE-2026-910216 days apartPath Traversal in Altium Enterprise Server ComparisonService Allows Arbitrary File Write
    37Monitor
  • CVE-2026-912916 days apartPath Traversal in Altium Enterprise Server Viewer StorageController Allows Arbitrary File Read
    37Monitor
  • CVE-2026-1443926 days apartPath Traversal in Altium Git Service Allows Remote Code Execution
    37Monitor
  • CVE-2026-114310 days apartPath Traversal in Altium Projects Service Allows Arbitrary File Read
    33Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-92808103 days apartServer-Side Request Forgery in Altium Enterprise Server UnifiedLogin Service Allows Unauthenticated System Compromise
    40Plan

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
X

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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

nvd-secondary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const file = path.join(ROOT, req.query.name);res.sendFile(file);

Fixed

ts
const file = path.resolve(ROOT, req.query.name);if (!file.startsWith(ROOT + path.sep)) {  return res.sendStatus(400);}res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records