CVE-2026-33170

Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, `SafeBuffer#%` does not propagate the `@html_unsafe` flag to the newly created buffer. If a `SafeBuffer` is mutated in place (e.g. via `gsub!`) and then formatted with `%` using untrusted arguments, the result incorrectly reports `html_safe? == true`, bypassing ERB auto-escaping and possibly leading to XSS. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7	Patch
https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2db	Patch
https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035beb	Patch
https://github.com/rails/rails/releases/tag/v7.2.3.1	Release Notes
https://github.com/rails/rails/releases/tag/v8.0.4.1	Release Notes
https://github.com/rails/rails/releases/tag/v8.1.2.1	Release Notes
https://github.com/rails/rails/security/advisories/GHSA-89vf-4333-qx8v	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:rubyonrails:rails::::::::
	cpe:2.3:a:rubyonrails:rails::::::::
	cpe:2.3:a:rubyonrails:rails::::::::

History

No history.

Information

Published : 2026-03-24 00:16

Updated : 2026-03-24 18:00

NVD link : CVE-2026-33170

Mitre link : CVE-2026-33170

CVE.ORG link : CVE-2026-33170

JSON object : View

Products Affected

rubyonrails

rails

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, `SafeBuffer#%` does not propagate the `@html_unsafe` flag to the newly created buffer. If a `SafeBuffer` is mutated in place (e.g. via `gsub!`) and then formatted with `%` using untrusted arguments, the result incorrectly reports `html_safe? == true`, bypassing ERB auto-escaping and possibly leading to XSS. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch."}, {"lang": "es", "value": "Active Support es un conjunto de herramientas de bibliotecas de soporte y extensiones del n\u00facleo de Ruby extra\u00eddas del framework de Rails. Antes de las versiones 8.1.2.1, 8.0.4.1 y 7.2.3.1, 'SafeBuffer#%' no propaga el flag '@html_unsafe' al b\u00fafer reci\u00e9n creado. Si un 'SafeBuffer' es mutado in situ (p. ej., a trav\u00e9s de 'gsub!') y luego formateado con '%' usando argumentos no confiables, el resultado informa incorrectamente que 'html_safe? == true', omitiendo el auto-escapado de ERB y posiblemente llevando a XSS. 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