@payloadcms/next has Stored XSS in Admin Panel

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-34748: 0.29% estimated exploitation activity in the next 30 days; percentile 21.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact 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. Consumers are affected if ALL of these are true: - Payload version < v3.78.0 - At least one collection with versions enabled - An authenticated user has create or update access to that collection Patches This vulnerability has been patched in v3.78.0. Output encoding has been added to prevent user-supplied content from being interpreted as markup. Users should upgrade to v3.78.0 or later. Workarounds If consumers cannot upgrade immediately: - Restrict create and update access to versioned collections to trusted roles only.

Published by the source

1 Apr 2026, 21:24 UTC

Last modified by the source

6 Apr 2026, 17:05 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-mmxc-95ch-2j7c

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-mmxc-95ch-2j7c

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# Patch Next advisory brief: CVE-2026-34748

Advisory: @payloadcms/next has Stored XSS in Admin Panel
IDs: CVE-2026-34748, GHSA-mmxc-95ch-2j7c
Record: https://patchnext.com/advisories/cve-2026-34748 (revision 2, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @payloadcms/next 3.78.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @payloadcms/next: affected < 3.78.0; fixed in 3.78.0

## Suggested inspection (read-only)
- `npm ls @payloadcms/next --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @payloadcms/next.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-mmxc-95ch-2j7c (OSV record GHSA-mmxc-95ch-2j7c lists affected ranges: npm @payloadcms/next >=0 <3.78.0 (fixed))
- Verified: https://github.com/advisories/GHSA-mmxc-95ch-2j7c (GitHub-reviewed advisory GHSA-mmxc-95ch-2j7c lists affected ranges: npm @payloadcms/next >=0 <3.78.0)

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