Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/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:N/R:U/V:D/RE:M/U:AmberSummary
CVE-2026-0279 is a low-severity Cross-site Scripting (CWE-79) vulnerability in Paloaltonetworks Pan-Os. Its CVSS base score is 1.3 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 25th 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-3 (Access Enforcement) and SC-7 (Boundary Protection) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-42682
Vulnerability Data
Multiple cross site scripting vulnerabilities in the User-ID™ Authentication Portal (aka Captive Portal) service, GlobalProtect™ gateway/portal features and Clientless VPN of Palo Alto Networks PAN-OS® software enables a malicious unauthenticated user to store or execute malicious JavaScript payload. The security…
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risk posed by this issue is minimized when the management interface and access to the User-ID™ Authentication Portal is restricted to only trusted internal IP addresses according to our recommended best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 . This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series). Cloud NGFW is not affected by this vulnerability.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stored/reflected XSS in the Captive Portal, GlobalProtect, and Clientless VPN components allows an unauthenticated attacker to deliver and execute malicious JavaScript in a victim's browser (T1189 Drive-by Compromise). The payload can leverage JavaScript (T1059.007) for further actions such as session hijacking or credential theft. The attack surface is limited to users accessing these portals, and best-practice network restrictions reduce exposure.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Boundary protection restricts the User-ID Authentication Portal and GlobalProtect interfaces to trusted internal IP addresses, directly blocking unauthenticated external attackers from reaching the XSS-vulnerable endpoints.
Access enforcement on the management and portal interfaces denies unauthenticated users the ability to submit or trigger malicious JavaScript payloads in the Captive Portal or Clientless VPN features.
Remote-access policy can mandate authenticated, encrypted channels and IP allow-lists for GlobalProtect and Clientless VPN, limiting exposure of the XSS-vulnerable portal surfaces.
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.
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).
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.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
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.
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.
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.
Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.