Script source hijacking via unvalidated Host headers
Published Aug 10, 2026 · Updated Aug 10, 2026
Host header injection in Pico through 2.1.4 allows remote attackers to control JavaScript and CSS asset origins in the default theme. Pico::getBaseUrl builds the base URL from unvalidated Host and X-Forwarded-* request headers, then propagates it into theme_url, assets_url, and plugins_url. Exploitation requires base_url to remain unset and user interaction; a crafted response makes the browser load attacker-hosted assets into the rendered page.
Summary
What happened
Host header injection in Pico through 2.1.4 allows remote attackers to control JavaScript and CSS asset origins in the default theme. Pico::getBaseUrl builds the base URL from unvalidated Host and X-Forwarded-* request headers, then propagates it into theme_url, assets_url, and plugins_url. Exploitation requires base_url to remain unset and user interaction; a crafted response makes the browser load attacker-hosted assets into the rendered page.
The record
- CVE
- CVE-2026-72574
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- Pico CMS
- Product
- Pico
- Classifications
- CWE-644, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 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 <=2.1.4
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.
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