CVE-2026-42099: Sparx Pro Cloud Server is vulnerable to a Race Condition in the /data_api/dl_internal_artifact.php endpoint. The application downloads the properties ...

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.

Metrics

CVSS 3.1

7.5/10

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

CVSS 4.0

7.7/10

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

EPSS Probability

0.72%

49.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Sparxsystems	Pro Cloud Server	<= 6.1.167

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.htmlExploit, Third Party Advisory

Timeline

Published: May 19, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-42099?

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.

How severe is CVE-2026-42099?

CVE-2026-42099 has a CVSS score of 7.7/10 (HIGH severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2026-42099?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.