CVE-2025-53939
Published: 29 November 2025
Summary
CVE-2025-53939 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Accellion Kiteworks. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 23.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-199894
Vulnerability details
Kiteworks is a private data network (PDN). Prior to version 9.1.0, improper input validation when managing roles of a shared folder could lead to unexpectedly elevate another user's permissions on the share. This issue has been patched in version 9.1.0.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The improper input validation vulnerability allows low-privileged network users to elevate another user's permissions on shared folders, facilitating exploitation for privilege escalation (T1068) and account manipulation via additional roles/permissions (T1098).
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.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Directly implements checks on information inputs to reject invalid data before processing.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.