How severe is CVE-2026-27210?

No CVSS score has been assigned to CVE-2026-27210 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-27210?

CVE-2026-27210 affects the following packages: pannellum (npm). Ecosystems affected: npm.

How do I fix CVE-2026-27210?

Update pannellum to 2.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27210 is resolved across your whole dependency graph.

How do I detect CVE-2026-27210 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pannellum. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-27210 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-27210?

O3 pinpoints whether CVE-2026-27210 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-27210 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27210 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 CVE-2026-27210?

CVE-2026-27210 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th 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.

When was CVE-2026-27210 published, and has it been updated?

CVE-2026-27210 was published on February 21, 2026 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-27210: Pannellum has a XSS vulnerability in hot spot a…

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk23th percentile+0.29%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦pannellum

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

1 total 1 fixed

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

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pannellum. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pannellum to 2.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27210 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27210 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-27210. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 i

O3 Security · Impact-Aware SCA

Is CVE-2026-27210 in your dependencies?

O3 detects CVE-2026-27210 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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CVE-2026-27210