Stored XSS via null-byte filter bypass
Published Sep 16, 2026 · Updated Sep 16, 2026
Stored XSS in BoldThemes Bold Page Builder 5.9.6 and earlier allows remote authenticated users to inject scripts through crafted content. The bt_bb_save_pre filter accepts a null-byte bypass, while bt_bb_raw_content emits base64-decoded shortcode_content without sufficient sanitization. Contributor-level access is required to save the payload, which executes in the browser of each user who opens the affected page.
Summary
What happened
Stored XSS in BoldThemes Bold Page Builder 5.9.6 and earlier allows remote authenticated users to inject scripts through crafted content. The bt_bb_save_pre filter accepts a null-byte bypass, while bt_bb_raw_content emits base64-decoded shortcode_content without sufficient sanitization. Contributor-level access is required to save the payload, which executes in the browser of each user who opens the affected page.
The record
- CVE
- CVE-2026-5920
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- BoldThemes
- Product
- Bold Page Builder
- Classifications
- T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=5.9.6
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
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
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo