CVE-2026-8621
Published: 14 May 2026
Summary
CVE-2026-8621 is a high-severity Improper Authentication (CWE-287) vulnerability. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Valid Accounts (T1078); ranked at the 28.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30369
Vulnerability details
Crabbox prior to v0.12.0 contains an authentication bypass vulnerability that allows non-admin shared-token callers to impersonate other owners or organizations by spoofing identity headers. Attackers can inject malicious X-Crabbox-Owner and X-Crabbox-Org headers in requests authenticated with a shared token to…
more
bypass authorization checks and access owner/org-scoped lease operations belonging to victim accounts.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Authentication bypass via header spoofing directly enables use of Valid Accounts (T1078) through impersonation and exploitation of a public-facing application (T1190).
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.
Detects unauthorized successful logons resulting from improper authentication implementations.
Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.
Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.
Session content review can reveal authentication bypasses or failures in session establishment.
Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.