{"cve":"CVE-2026-33170","nvd":{"published":"2026-03-24T00:16:28.287","modified":"2026-06-17T10:37:04.360","status":"Analyzed","description":"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_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","score":5.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7","https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2db","https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035beb","https://github.com/rails/rails/releases/tag/v7.2.3.1","https://github.com/rails/rails/releases/tag/v8.0.4.1"],"products":["rubyonrails:rails"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-33170","score":0.0034,"percentile":0.2752,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-89vf-4333-qx8v","url":"https://osv.dev/vulnerability/GHSA-89vf-4333-qx8v","summary":"Rails Active Support has a possible XSS vulnerability in SafeBuffer#%","modified":"2026-09-10T03:50:38.175334274Z","packages":[{"ecosystem":"RubyGems","name":"activesupport","purl":"pkg:gem/activesupport","ranges":[">=8.1.0.beta1 <8.1.2.1"],"fixed":["8.1.2.1"]},{"ecosystem":"RubyGems","name":"activesupport","purl":"pkg:gem/activesupport","ranges":[">=8.0.0.beta1 <8.0.4.1"],"fixed":["8.0.4.1"]},{"ecosystem":"RubyGems","name":"activesupport","purl":"pkg:gem/activesupport","ranges":["<7.2.3.1"],"fixed":["7.2.3.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}