CVE-2026-42099: Sparxsystems Pro Cloud Server remote code execution (CVSS 7.5)

Description

Sparx Pro Cloud Server is vulnerable to a Race Condition in the /data_api/dl_internal_artifact.php endpoint. The application downloads the properties of the object pointed by guid parameter and saves loaded content in current location (__DIR__) under the specified name. An attacker with repository access can control both the filename and file contents, allowing the creation of a malicious PHP file in a current directory. Although the file is deleted after processing, a race condition exists: if the response transmission is delayed (e.g., via a large file or slow client connection), the file remains accessible. During this window, the attacker can issue a second request to execute the malicious PHP file, resulting in remote code execution. The vendor was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Only version 6.1 (build 167) and below were tested and confirmed as vulnerable, other versions were not tested and might also be vulnerable.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityHigh

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Sparxsystems Pro Cloud Server≤ 6.1.167

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

https://cert.pl/en/posts/2026/05/CVE-2026-42096Third Party Advisory
https://efigo.pl/blog/CVE-2026-42096/Third Party Advisory
https://sparxsystems.com/products/procloudserver/Product
https://sploit.tech/2026/05/19/Sparx-Enterprise-Architect-PCS.htmlExploitThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-42099 being actively exploited?

CVE-2026-42099 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.66%.

How severe is CVE-2026-42099?

CVE-2026-42099 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.66% probability of exploitation.

Which products are affected by CVE-2026-42099?

Affected products include Sparxsystems Pro Cloud Server.

How do I fix CVE-2026-42099?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-42099 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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