What is the CVSS score of CVE-2026-27210?

CVE-2026-27210 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.1%.

Which versions of Pannellum are affected by CVE-2026-27210?

Organizations using versions 3.5.0 should be aware of moderate risk from CVE-2026-27210, a cross-site scripting vulnerability rated CVSS 6.1.. A patch is available.

How to fix or mitigate CVE-2026-27210?

Within 30 days: Identify affected systems running versions 3.5.0 and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Pannellum CVE-2026-27210

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-02-21 security-advisories@github.com

GHSA-8423-w5wx-h2r6

XSS Pannellum

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:04 vuln.today

Patch released

Mar 02, 2026 - 15:21 nvd

Patch available

CVE Published

Feb 21, 2026 - 06:17 nvd

MEDIUM 6.1

DescriptionGitHub Advisory

Pannellum is a lightweight, free, and open source panorama viewer for the web. In versions 3.5.0 through 2.5.6, the hot spot attributes configuration property allowed any attribute to be set, including HTML event handler attributes, allowing for potential XSS attacks. This affects websites hosting the standalone viewer HTML file and any other use of untrusted JSON config files (bypassing the protections of the escapeHTML parameter). As certain events fire without any additional user interaction, visiting a standalone viewer URL that points to a malicious config file - without additional user interaction - is sufficient to trigger the vulnerability and execute arbitrary JavaScript code, which can, for example, replace the contents of the page with arbitrary content and make it appear to be hosted by the website hosting the standalone viewer HTML file. This issue has been fixed in version 2.5.7. To workaround, setting the Content-Security-Policy header to script-src-attr 'none' will block execution of inline event handlers, mitigating this vulnerability. Don't host pannellum.htm on a domain that shares cookies with user authentication to mitigate XSS risk.

AnalysisAI

Pannellum 2.5.0 through 2.5.6 allows arbitrary JavaScript execution through improperly sanitized hotspot configuration attributes in JSON files, enabling stored XSS attacks against users viewing panorama viewers with malicious configurations. An attacker can craft a malicious config file that executes code automatically upon page load without user interaction, potentially allowing page defacement or credential theft. A patch is available to address this vulnerability.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Pannellum. Pannellum is a lightweight, free, and open source panorama viewer for the web. In versions 3.5.0 through 2.5.6, the hot spot attributes configuration property allowed any attribute to be set, including HTML event handler attributes, allowing for potential XSS attacks. This affects websites hosting the standalone viewer HTML file and any other use of untrusted JSON config files (bypassing the protections of the escapeHTML parameter). As certain events fire without any additional user interaction,

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 2.5.7.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.