Tina: Broken Access Control: arbitrary bucket-key write/delete in next-tinacms-s3 (and sibling production media adapters)

Exploitation

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

CVSS

5.4 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

EPSS

• CVE-2026-59992: 0.38% estimated exploitation activity in the next 30 days; percentile 32.05 (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.

Summary The production media handler shipped by next-tinacms-s3 (createMediaHandler in packages/next-tinacms-s3/src/handlers.ts) accepts an attacker-chosen ?key= query parameter and returns an AWS-signed PutObject URL whose Key is that value, with no check that the key falls under the operator's configured mediaRoot. The same handler's DELETE branch reads objectKey = (req.query.media as string[])[1] and dispatches a DeleteObjectCommand for that exact key, again unbounded by mediaRoot. Any caller that passes the operator-supplied authorized() predicate — i.e. any logged-in CMS editor in a typical TinaCloud / self-hosted deployment — therefore has write and delete authority over the entire S3 bucket the IAM key can reach, even though the package documents mediaRoot as the place where editors are scoped. The same shape is present in next-tinacms-dos, next-tinacms-azure, and next-tinacms-cloudinary, so a single design mistake spans every first-party production media backend. Project:…

Published by the source

19 Aug 2026, 21:56 UTC

Last modified by the source

21 Aug 2026, 18:31 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8mq9-5fw2-5rm4

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# Patch Next advisory brief: CVE-2026-59992

Advisory: Tina: Broken Access Control: arbitrary bucket-key write/delete in `next-tinacms-s3` (and sibling production media adapters)
IDs: CVE-2026-59992, GHSA-8mq9-5fw2-5rm4
Record: https://patchnext.com/advisories/cve-2026-59992 (revision 1, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: next-tinacms-s3 23.0.4; next-tinacms-azure 14.0.4; next-tinacms-dos 23.0.4; next-tinacms-cloudinary 26.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm next-tinacms-s3: affected < 23.0.4; fixed in 23.0.4
- npm next-tinacms-azure: affected < 14.0.4; fixed in 14.0.4
- npm next-tinacms-dos: affected < 23.0.4; fixed in 23.0.4
- npm next-tinacms-cloudinary: affected < 26.0.4; fixed in 26.0.4

## Suggested inspection (read-only)
- `npm ls next-tinacms-s3 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls next-tinacms-azure --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls next-tinacms-dos --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls next-tinacms-cloudinary --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 next-tinacms-s3, next-tinacms-azure, next-tinacms-dos, next-tinacms-cloudinary.
- 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://github.com/advisories/GHSA-8mq9-5fw2-5rm4 (GitHub-reviewed advisory GHSA-8mq9-5fw2-5rm4 lists affected ranges: npm next-tinacms-s3 >=0 =0 =0 =0 <26.0.4)

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