Stored XSS via Critical CSS token bypass
Published Aug 19, 2026 · Updated Aug 19, 2026
Stored XSS in 10Web Booster before 2.33.5 allows remote attackers to execute JavaScript in visitors' browsers via crafted Critical CSS content. An unauthenticated request handler accepts a weakly validated access token and then renders attacker-supplied stylesheet content into the page head without escaping, turning stored CSS into executable markup. No account is required, but a victim must load an affected page; impact is limited to browser-side script execution against page visitors rather than direct server-side code execution.
Summary
What happened
Stored XSS in 10Web Booster before 2.33.5 allows remote attackers to execute JavaScript in visitors' browsers via crafted Critical CSS content. An unauthenticated request handler accepts a weakly validated access token and then renders attacker-supplied stylesheet content into the page head without escaping, turning stored CSS into executable markup. No account is required, but a victim must load an affected page; impact is limited to browser-side script execution against page visitors rather than direct server-side code execution.
The record
- CVE
- CVE-2026-14287
- Published
- Aug 19, 2026
- Updated
- Aug 19, 2026
- Vendor
- 10Web
- Product
- 10Web Booster
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 19, 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=0 <2.33.5
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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