CVE-2026-125398 json
Instatic before 0.0.21 Authorization Bypass via Row Author Reassignment Endpoint
published 9d ago modified 2d ago also EUVD-2026-120561 , GHSA-m425-wmrc-4v4v
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository CoreBunch/Instatic. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 20%
- public exploits
- 0
- none known
Summary
Instatic before 0.0.21 contains an authorization bypass vulnerability in handleRowAuthor that allows authenticated users to skip table-level access checks by loading rows with getDataRow() instead of loadRowForAccess(). Attackers holding content.edit.any but lacking data.system.tables.read can send PATCH requests to /admin/api/cms/data/rows/:id/author to read system-table rows and reassign their authors.
Patch / fix
- CoreBunch Instatic 0.0.21
Is CVE-2026-125398 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N |
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N |
Affected products
- CoreBunch Instatic
Classification
- Weakness
-
- CWE-862 Missing Authorization
References
-
github.com
/CoreBunch/Instatic/commit/ff1e51eb59c860864fa24e8c3e2716b56314f3ad
patch
-
github.com
/CoreBunch/Instatic/security/advisories/GHSA-m425-wmrc-4v4v
vendor-advisory, advisory
-
github.com
/CoreBunch/Instatic/releases/tag/v0.0.21
release-notes
-
github.com
/CoreBunch/Instatic/blob/v0.0.20/server/handlers/cms/data/rows.ts#L378-L398
technical-description
-
vulncheck.com
/advisories/instatic-before-0.0.21-authorization-bypass-via-row-author-reassignment-endpoint
third-party-advisory
Sources
- CVE List CVE-2026-125398
- NVD CVE-2026-125398
- Maintainer advisory GHSA-m425-wmrc-4v4v
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of CoreBunch/Instatic published their own advisory on GitHub. Reviewed sources take precedence over it.