CVE-2026-34748
HIGHCVE-2026-34748 is a high-severity (CVSS 8.7) Cross-site Scripting (XSS) vulnerability in @payloadcms/next. O3 Security confirms whether CVE-2026-34748 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
@payloadcms/next has Stored XSS in Admin Panel
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@payloadcms/nextnpmDescription
Payload is a free and open source headless content management system. Prior to version 3.78.0 in @payloadcms/next, a stored Cross-Site Scripting (XSS) vulnerability existed in the admin panel. An authenticated user with write access to a collection could save content that, when viewed by another user, would execute in their browser. This issue has been patched in version 3.78.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @payloadcms/next | all versions | 3.78.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @payloadcms/next. 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 @payloadcms/next to 3.78.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34748 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-2026-34748 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-2026-34748. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-34748 in your dependencies?
O3 detects CVE-2026-34748 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.