How severe is GHSA-8423-w5wx-h2r6?

No CVSS score has been assigned to GHSA-8423-w5wx-h2r6 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8423-w5wx-h2r6?

GHSA-8423-w5wx-h2r6 affects the following packages: pannellum (npm). Ecosystems affected: npm.

How do I fix GHSA-8423-w5wx-h2r6?

Update pannellum to 2.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8423-w5wx-h2r6 is resolved across your whole dependency graph.

How do I detect GHSA-8423-w5wx-h2r6 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pannellum, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-8423-w5wx-h2r6 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-8423-w5wx-h2r6 actively exploited in the wild?

No public exploit code has been indexed for GHSA-8423-w5wx-h2r6 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-8423-w5wx-h2r6?

GHSA-8423-w5wx-h2r6 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-8423-w5wx-h2r6?

GHSA-8423-w5wx-h2r6 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-8423-w5wx-h2r6 published, and has it been updated?

GHSA-8423-w5wx-h2r6 was published on February 19, 2026 and was last updated on February 23, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Pannellum has a XSS vulnerability in hot spot attributesGHSA-8423-w5wx-h2r6

Fix: mpetroff/pannellum@9391ef8

GHSA-8423-w5wx-h2r6 is a Cross-site Scripting (XSS) vulnerability in pannellum. A fix is available for pannellum — see the affected versions and patch details below.

Also known asCVE-2026-27210

Published

Feb 19, 2026

Updated

Feb 23, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-8423-w5wx-h2r6.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

33other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

pannellumnpm

44Kdownloads / week

Description

Impact

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.

Patches

This has been fixed both in v2.5.7 and in the current development branch.

Workarounds

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.

Acknowledgments

Reported both by luminary (@lumin9ry), Visvge (@Sicclord1 / @Visvge), and sutol (@0x5a6163 / @SUT0L) and by another researcher who wishes not to be named at this time.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`pannellum`	≥ 2.5.0&&< 2.5.7	2.5.7`npm install pannellum@2.5.7`

Affected Products

1 product · 1 configurations

Application

pannellumpannellum

≥ 2.5.0 && < 2.5.7

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pannellum, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pannellum to 2.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8423-w5wx-h2r6 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact 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