CVE-2026-42099
Published: 19 May 2026
Summary
CVE-2026-42099 is a high-severity Race Condition (CWE-362) vulnerability in Sparxsystems Pro Cloud Server. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 45.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30929
- 🇵🇱 CERT-PL: cert.pl
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Race condition in public web endpoint enables creation and execution of attacker-controlled PHP web shell before deletion.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.
Coordination of concurrent security activities reduces the probability that shared resources will be accessed simultaneously without proper synchronization.