Which versions of BloodHound are affected by CVE-2026-59255?

BloodHound through version 9.4.0 contains a privilege escalation vulnerability that enables any logged-in user to alter or delete identity schema elements used across the entire organization.. A patch is available.

Is there a public PoC exploit available for CVE-2026-59255?

Yes, a public proof-of-concept exploit is available for CVE-2026-59255. Prioritise patching immediately. EPSS: 0.2%.

How to fix or mitigate CVE-2026-59255?

Within 24 hours, identify your current BloodHound deployment version and confirm whether you are running 9.4.0 or earlier. Within 7 days, apply the vendor-released patch (commit 8f79035) to your BloodHound instance, or upgrade to the patched version released by SpecterOps. Within 30 days, validate successful patch application, review role-based access controls on custom node schema management, and confirm that non-administrative users can no longer modify shared schema constructs.

BloodHound CVE-2026-59255

Q: What is the CVSS score of CVE-2026-59255?

CVE-2026-59255 has a CVSS 4.0 base score of 7.1 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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:X. EPSS exploitation probability: 0.2%.

EUVD-2026-44754 HIGH

Missing Authorization (CWE-862)

2026-07-15 VulnCheck

GHSA-7qmq-x64g-8v7j

Authentication Bypass Bloodhound

7.1

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

7.1 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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:X

vuln.today AI

7.1 HIGH

Network-reachable API with any authenticated user (PR:L, AC:L, UI:N); impact is integrity to the shared schema (I:H) with minor availability loss (A:L) and no confidentiality exposure.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Source Code Evidence Fetched

Jul 15, 2026 - 17:47 vuln.today

Analysis Generated

Jul 15, 2026 - 17:47 vuln.today

CVE Published

Jul 15, 2026 - 17:03 cve.org

HIGH 7.1

DescriptionCVE.org

BloodHound through 9.4.0, fixed in commit 8f79035, contains a missing authorization vulnerability in the custom-nodes API endpoints that allows any authenticated user to modify the global graph schema. Attackers with valid session tokens can create, update, or delete custom node types affecting all users and tenants by invoking unprotected POST, PUT, and DELETE operations on the custom-nodes endpoints.

AnalysisAI

Improper authorization in SpecterOps BloodHound through 9.4.0 lets any authenticated user tamper with the global custom-node graph schema by calling POST, PUT, and DELETE operations on the /api/v2/custom-nodes endpoints, which enforced only that a caller was logged in rather than that they held write permissions. Because custom node kinds are a shared, tenant-wide schema construct, a single low-privileged account can create, alter, or delete node types that affect every user and tenant on the instance. Publicly available exploit code exists and a vendor patch (commit 8f79035) is available; there is no CISA KEV listing, so exploitation is not confirmed as active.

Technical ContextAI

BloodHound is an Active Directory / Entra ID attack-path analysis platform (SpecterOps) whose backend API is written in Go. The custom-nodes API manages 'custom node kinds' - user-defined node types that extend the graph schema used across the whole deployment (OpenGraph). The root cause is CWE-862 (Missing Authorization): per the PR diff in cmd/api/src/api/registration/v2.go, the mutating routes were registered with .RequireAuth() (any valid session) instead of a permission gate. The fix rebinds reads to permissions.OpenGraphRead and the POST/PUT/DELETE mutations to permissions.OpenGraphWrite, so the flaw is an authorization-check gap where authentication was conflated with authorization, not a code-execution or injection bug.

RemediationAI

Upgrade to a BloodHound release that includes the fix commit 8f790351349fd87bcb04377aba84cba6495825b3 (merged via PR #2989), which changes the custom-nodes routes from RequireAuth() to permission-gated RequirePermissions(OpenGraphRead) for reads and RequirePermissions(OpenGraphWrite) for the POST/PUT/DELETE mutations; a released patched version number is not stated in the input, so confirm the exact tagged release against the SpecterOps advisory before deploying. If you cannot patch immediately, restrict which accounts can reach the API and minimize the number of low-privileged users, place the BloodHound API behind network controls or a reverse proxy that blocks POST/PUT/DELETE to /api/v2/custom-nodes for non-administrative principals (trade-off: this also blocks legitimate custom-node management), and monitor for unexpected creation/modification/deletion of custom node kinds. Full remediation details are in the VulnCheck advisory (https://www.vulncheck.com/advisories/bloodhound-missing-authorization-on-custom-node-management-api) and PR https://github.com/SpecterOps/BloodHound/pull/2989.