Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/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:XSummary
CVE-2026-63765 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and IA-8 (Identification and Authentication (Non-organizational Users)) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-48360
Vulnerability Data
Chatwoot before 4.16.0 contains an authentication bypass vulnerability in the direct uploads controller that allows unauthenticated attackers to create arbitrary ActiveStorage blobs in any tenant account. Attackers can exploit missing authentication checks to resolve any account and conversation, then obtain…
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signed PUT URLs to write arbitrary data to the application's storage backend.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Authentication bypass in public-facing upload controller directly enables exploitation of the web application to write arbitrary data.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 6 hardening rules · 3 OS baselines
V6.2.3V6.4.4V10.4.16V12.1.3
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces authentication and authorization checks on the direct uploads controller before allowing blob creation or signed URL issuance.
Requires identification and authentication of non-organizational users before permitting any access to tenant-specific upload functionality.
Boundary protection mechanisms can restrict unauthenticated network access to the vulnerable uploads endpoint and storage backend.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.
Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.
Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.
Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
The control explicitly calls for authentication before any critical function is reached, eliminating the possibility of bypassing authentication for high-value operations.
Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.
Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.
Security engineering principles insist on authentication and authorization for every critical function, eliminating entry points that lack any access control mechanism.
Requiring strong authentication and access-privilege enablement for remote connections ensures that critical functions cannot be invoked without proper verification, closing a gap that would otherwise allow unauthenticated use.
Mandatory use of access cards, biometrics, or two-factor authentication ensures that critical physical areas cannot be entered without proper authentication.