Stored XSS via unsanitized extension error rendering
Published Jul 3, 2026 · Updated Jul 3, 2026
Stored XSS in Gitea 1.25.0 before 1.26.0 allows remote authenticated users to run JavaScript when another user views a crafted glTF file. The 3D viewer places attacker-controlled extensionsRequired names in an unsupported-extension error and writes the message to the DOM with innerHTML without sanitization. Repository write access is required to store the file, and exploitation occurs when another user opens its page, exposing that user's session and same-origin actions.
Summary
What happened
Stored XSS in Gitea 1.25.0 before 1.26.0 allows remote authenticated users to run JavaScript when another user views a crafted glTF file. The 3D viewer places attacker-controlled extensionsRequired names in an unsupported-extension error and writes the message to the DOM with innerHTML without sanitization. Repository write access is required to store the file, and exploitation occurs when another user opens its page, exposing that user's session and same-origin actions.
The record
- CVE
- CVE-2026-28737
- Published
- Jul 3, 2026
- Updated
- Jul 3, 2026
- Vendor
- Gitea
- Product
- Gitea
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 3, 2026CVE publishedPublication date reported by the CVE source.
- Jul 3, 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=1.25.0 <1.26.0
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.
Weakness, pattern, technique
Public exploit references
- Minimal glTF extensionsRequired stored-XSS proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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