Cross-origin file writes via unenforced CORS policy
Published Aug 19, 2026 · Updated Aug 25, 2026
Cross-site request forgery in TinaCMS CLI before 2.5.2 allows remote attackers to write files into the configured media root. The Vite CORS origin callback returns false for disallowed origins without rejecting requests, so the upload route processes attacker-controlled multipart data. Exploitation requires a developer to run tinacms dev and visit an attacker-controlled page; impact is limited to file creation inside the media root.
Summary
What happened
Cross-site request forgery in TinaCMS CLI before 2.5.2 allows remote attackers to write files into the configured media root. The Vite CORS origin callback returns false for disallowed origins without rejecting requests, so the upload route processes attacker-controlled multipart data. Exploitation requires a developer to run tinacms dev and visit an attacker-controlled page; impact is limited to file creation inside the media root.
The record
- CVE
- CVE-2026-63123
- Published
- Aug 19, 2026
- Updated
- Aug 25, 2026
- Vendor
- TinaCMS
- Product
- TinaCMS
- Classifications
- CWE-352, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.5.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- GHSA-rgr9-r7mj-mf6x browser reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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