{"id":"CVE-2023-28120","aliases":["GHSA-pj73-v5mw-pm9j"],"url":"https://o3.security/vulnerability/CVE-2023-28120","summary":"Possible XSS Security Vulnerability in SafeBuffer#bytesplice","details":"There is a vulnerability in ActiveSupport if the new bytesplice method is called on a SafeBuffer with untrusted user input.\nThis vulnerability has been assigned the CVE identifier CVE-2023-28120.\n\nVersions Affected: All. Not affected: None Fixed Versions: 7.0.4.3, 6.1.7.3\n\n# Impact\n\nActiveSupport uses the SafeBuffer string subclass to tag strings as html_safe after they have been sanitized.\nWhen these strings are mutated, the tag is should be removed to mark them as no longer being html_safe.\n\nRuby 3.2 introduced a new bytesplice method which ActiveSupport did not yet understand to be a mutation.\nUsers on older versions of Ruby are likely unaffected.\n\nAll users running an affected release and using bytesplice should either upgrade or use one of the workarounds immediately.\n\n# Workarounds\n\nAvoid calling bytesplice on a SafeBuffer (html_safe) string with untrusted user input.\n","published":"2025-01-09T00:33:47.658Z","modified":"2026-09-09T03:45:31.056884336Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":{"score":0.00923,"percentile":0.5672,"asOf":"2026-07-28"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"RubyGems","name":"activesupport","fixedVersion":"7.0.4.3"},{"ecosystem":"RubyGems","name":"activesupport","fixedVersion":"6.1.7.3"}],"fix":{"url":"https://github.com/rails/rails/commit/3cf23c3f891e2e81c977ea4ab83b62bc2a444b70","label":"rails/rails@3cf23c3"},"references":[{"type":"WEB","url":"https://discuss.rubyonrails.org/t/cve-2023-28120-possible-xss-security-vulnerability-in-safebuffer-bytesplice/82469"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UPV6PVCX4VDJHLFFT42EXBBSGAWZICOW/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZE5W4MH6IE4DV7GELDK6ISCSTFLHKSYO/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/28xxx/CVE-2023-28120.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-28120"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20240202-0006/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2023/dsa-5389"},{"type":"FIX","url":"https://github.com/rails/rails/commit/3cf23c3f891e2e81c977ea4ab83b62bc2a444b70"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activesupport/CVE-2023-28120.yml"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UPV6PVCX4VDJHLFFT42EXBBSGAWZICOW"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZE5W4MH6IE4DV7GELDK6ISCSTFLHKSYO"},{"type":"WEB","url":"https://security.netapp.com/advisory/ntap-20240202-0006"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-09T03:45:31.056884336Z"}}