Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/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-2026-23517 is a medium-severity Missing Authorization (CWE-862) vulnerability in Fleetdm Fleet. 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 16th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23517 is a broken access control vulnerability (CWE-862) in Fleet, an open source device management software. It affects versions prior to 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, where debug and profiling endpoints (debug/pprof) are accessible to any authenticated user regardless of role. This enables low-privilege users, such as those with the Observer role, to view internal server diagnostics, including runtime profiling data and in-memory application state. The issue has a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H), indicating high confidentiality and availability impacts.
Any authenticated user with low privileges can exploit this vulnerability over the network with low complexity and no user interaction required. Attackers can retrieve sensitive server internals, potentially exposing operational details, and trigger resource-intensive CPU profiling operations that lead to denial of service by overwhelming the server.
Fleet's security advisory and commit fix the issue in versions 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3. As a workaround if upgrading is not immediately possible, administrators should place the debug/pprof endpoints behind an IP allowlist. Details are available in the GitHub security advisory (GHSA-4r5r-ccr6-q6f6) and the patching commit (5c030e32a3a9bc512355b5e1bf19636e4e6d0317).
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3349
Vulnerability Data
Fleet is open source device management software. A broken access control issue in versions prior to 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3 allowed authenticated users to access debug and profiling endpoints regardless of role. As a result, low-privilege users could…
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view internal server diagnostics and trigger resource-intensive profiling operations. Fleet’s debug/pprof endpoints are accessible to any authenticated user regardless of role, including the lowest-privilege “Observer” role. This allows low-privilege users to access sensitive server internals, including runtime profiling data and in-memory application state, and to trigger CPU-intensive profiling operations that could lead to denial of service. Versions 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3 fix the issue. If an immediate upgrade is not possible, users should put the debug/pprof endpoints behind an IP allowlist as a workaround.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 3 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly requires enforcement of authorization decisions on every access request, structurally eliminating missing authorization checks.
AC-24 mandates that access control decisions are applied to each request, preventing bypass of authorization logic.
AC-25 requires a tamperproof, always-invoked reference monitor that ensures authorization checks cannot be omitted.
AC-6 reduces the set of actions reachable without proper authorization, limiting blast radius of missing checks.
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.
Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.
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.
Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.
Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.
Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.
Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.
By requiring competent outsiders to verify that every function enforces the need-to-know principle, the control lowers the likelihood that missing authorization checks persist undetected.
Defining authorization responsibilities and reviewing risk-treatment progress throughout the project lifecycle catches missing authorization checks before the system is deployed.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-862
- V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
RHEL 7 (2 rules)
- V-251704 The Red Hat Enterprise Linux operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
- V-204429 The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation. prevents CWE-862