What’s Vulnerable › Vulnerabilities

CVE-2026-89145: Flextype CMS 0.9.9 through 1.0.0-alpha.3 Stored XSS via Plugin Directory

• Severity: medium (CVSS 4.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-11 · updated 2026-09-24
• Weakness: CWE-79

Description

Flextype CMS versions 0.9.9 through 1.0.0-alpha.3 fail to HTML-escape plugin directory names in the dependency error page rendered by getValidPluginsDependencies(). Attackers with write access to the plugins directory can create a plugin with HTML characters in its name to execute arbitrary scripts in users' browsers when dependency validation fails.

Affected products

• flextype: from 0.9.9 through 1.0.0-alpha.3

References

• https://github.com/flextype/flextype
• https://github.com/flextype/flextype/blob/aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d/src/flextype/core/Plugins.php#L345
• https://github.com/flextype/flextype/issues/597
• https://www.vulncheck.com/advisories/flextype-cms-0.9.9-through-1.0.0-alpha.3-stored-xss-via-plugin-directory

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