CVE-2026-125398: CoreBunch Instatic · Missing Authorization
Affects CoreBunch InstaticSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 0.0.21 soon.
Data as of 9 Nov 2026, 23:50 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 7.1 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.1 |
- Patch
- Available – fixed in 0.0.21
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade CoreBunch Instatic to 0.0.21.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CoreBunchInstatic | Affected
| Fixed in
|
GitHubInstaticpkg:github/InstaticOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Instatic to version 0.0.21 or later, where this authorization bypass vulnerability is fixed. No other mitigation is indicated by the vendor advisory.
Description
CVE-2026-125398 is an authorization bypass vulnerability in CoreBunch's Instatic product versions before 0.0.21. It allows authenticated users with the content.edit.any permission but without data.system.tables.read permission to bypass table-level access controls. Attackers can exploit this by sending PATCH requests to the /admin/api/cms/data/rows/:id/author endpoint to read system-table rows and reassign their authors.
References
- github.com/CoreBunch/Instatic/security/advisories/GHSA-m425-wmrc-4v4v (opens in a new tab)
- github.com/CoreBunch/Instatic/commit/ff1e51eb59c860864fa24e8c3e2716b56314f3ad (opens in a new tab)
- github.com/CoreBunch/Instatic/releases/tag/v0.0.21 (opens in a new tab)
- github.com/CoreBunch/Instatic/blob/v0.0.20/server/handlers/cms/data/rows.ts (opens in a new tab)
- vulncheck.com/advisories/instatic-before-0.0.21-authorization-bypass-via-row-author-reassignment-endpoint (opens in a new tab)