cbcvebase.
CVE-2026-33170
published 2026-03-24

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…

medium5.3CVSS 4.0
AVNACLATNPRNUIPVCNVILVANSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
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.

Affected

10 ranges
VendorProductVersion rangeFixed in
debianrails
railsactivesupport< 7.2.3.17.2.3.1
railsactivesupport
railsactivesupport
railsactivesupport>= 0 < 7.2.3.17.2.3.1
railsactivesupport>= 8.0.0.beta1 < 8.0.4.18.0.4.1
railsactivesupport>= 8.1.0.beta1 < 8.1.2.18.1.2.1
rubyonrailsrails< 7.2.3.17.2.3.1
rubyonrailsrails>= 8.0.0 < 8.0.4.18.0.4.1
rubyonrailsrails>= 8.1.0 < 8.1.2.18.1.2.1

CVSS provenance

nvdv4.05.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
osv5.3MEDIUM