Cyber Resilience

CVE-2026-27009

XSS in Openclaw ≤ 2026.2.15

Public PoCXSS
Published
20 February 2026
Modified
20 February 2026
Patch / advisory
CVSS Score v3.1 5.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0023 14th percentile
Risk Priority 39 floored blend · peak EPSS

Summary

CVE-2026-27009 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Openclaw Openclaw. Its CVSS base score is 5.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 14th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as Enterprise AI Assistants; in the Other ATLAS/OWASP Terms risk domain.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OpenClaw is a personal AI assistant. Prior to version 2026.2.15, a atored XSS issue in the OpenClaw Control UI when rendering assistant identity (name/avatar) into an inline `<script>` tag without script-context-safe escaping. A crafted value containing `</script>` could break out…

more

of the script tag and execute attacker-controlled JavaScript in the Control UI origin. Version 2026.2.15 removed inline script injection and serve bootstrap config from a JSON endpoint and added a restrictive Content Security Policy for the Control UI (`script-src 'self'`, no inline scripts).

CWE(s)

AI Security AnalysisAI

AI Category
Enterprise AI Assistants
Risk Domain
Other ATLAS/OWASP Terms
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: ai

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
Why these techniques?

Stored XSS enables arbitrary JS execution in browser origin, directly facilitating browser session hijacking and web session cookie theft.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-27293Shared CWE-79
CVE-2023-46003Shared CWE-79
CVE-2023-5343Shared CWE-79
CVE-2023-46650Shared CWE-79
CVE-2023-49272Shared CWE-79
CVE-2023-49271Shared CWE-79
CVE-2023-46659Shared CWE-79
CVE-2023-46287Shared CWE-79
CVE-2023-49490Shared CWE-79
CVE-2023-5894Shared CWE-79

Affected Assets

openclaw
openclaw
≤ 2026.2.15

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-15 Information Output Filtering
  • SI-3 Malicious Code Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation and sanitization of untrusted input (assistant name/avatar) before it is rendered into HTML/script contexts, blocking the stored XSS payload.

prevent

Mandates output filtering/encoding of application data, which would have prevented the raw identity value from being emitted inside an inline <script> tag without context-safe escaping.

prevent

Requires malicious-code protection mechanisms (e.g., CSP enforcement or WAF rules) that can block execution of injected scripts even if input validation fails, matching the CSP added in the fix.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

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.

detects

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

none

Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.

References