Stored XSS via unsanitized SVG upload
Published Mar 8, 2026 · Updated Mar 8, 2026
Stored XSS in Bytedesk 1.3.0 through 1.3.9 allows remote authenticated users to execute JavaScript via an uploaded SVG file. The uploadFile path accepts image/svg+xml content, stores embedded script without sanitization, and returns a URL that serves the file directly. A valid token and a victim visit to that URL are required; the script then runs in the site's browser origin.
Summary
What happened
Stored XSS in Bytedesk 1.3.0 through 1.3.9 allows remote authenticated users to execute JavaScript via an uploaded SVG file. The uploadFile path accepts image/svg+xml content, stores embedded script without sanitization, and returns a URL that serves the file directly. A valid token and a victim visit to that URL are required; the script then runs in the site's browser origin.
The record
- CVE
- CVE-2026-3748
- Published
- Mar 8, 2026
- Updated
- Mar 8, 2026
- Vendor
- Beijing Weiyu Tianxia Technology Co., Ltd.
- Product
- Bytedesk
- Classifications
- CWE-434, CWE-284, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 8, 2026CVE publishedPublication date reported by the CVE source.
- Mar 8, 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=1.3.0
- Affected versionversion=1.3.1
- Affected versionversion=1.3.2
- Affected versionversion=1.3.3
- Affected versionversion=1.3.4
- Affected versionversion=1.3.5
- Affected versionversion=1.3.6
- Affected versionversion=1.3.7
- Affected versionversion=1.3.8
- Affected versionversion=1.3.9
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
- Authenticated malicious SVG upload 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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