CVE-2026-21821
Published: 13 May 2026
Summary
CVE-2026-21821 is a high-severity Use of Unmaintained Third Party Components (CWE-1104) vulnerability in Hcl Software (inferred from references). Its CVSS base score is 8.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 11.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30155
Vulnerability details
The HCL BigFix SCM Reporting site contains an outdated and unsupported version of the jQuery 1.x library. Since jQuery 1.x has reached end-of-life and no longer receives security updates, it may expose the application to publicly known security weaknesses and…
more
increase the risk of client-side attacks such as Cross-Site Scripting (XSS) or manipulation through vulnerable third-party components.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Outdated jQuery enables XSS leading to drive-by compromise and client-side execution.
CVEs Like This One
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 groups frequently discuss maintenance status of third-party components, aiding identification and avoidance of unmaintained ones.
Maintaining an accurate, reviewed inventory of all system components enables tracking of third-party software versions and maintenance status, reducing the risk of using unmaintained components.
The maintenance policy requires regular updates and upkeep of systems and third-party components, directly reducing the presence of unmaintained software that attackers can exploit.
Requiring quick access to maintenance support and spare parts after failure necessitates using actively supported components rather than unmaintained third-party ones.
Contact with security communities directly informs personnel of unmaintained components and their vulnerabilities, reducing the likelihood of their continued use.
Threat intelligence sharing directly informs organizations of newly discovered vulnerabilities and exploitation in third-party components, enabling timely updates or replacement before attackers can leverage them.
Resource allocation in investment requests funds regular maintenance, patching, and updates of third-party components.
Organization-wide SCRM policy includes ongoing evaluation of third-party component support lifecycles to avoid unmaintained dependencies.