{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "8.1.0.beta1"
              },
              {
                "fixed": "8.1.2.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "80827ca7ff33ca3026f2c74fe8249ccc6f513318"
            },
            {
              "fixed": "1db4b89687cc18311fc3f92623136705df24e671"
            }
          ],
          "repo": "https://github.com/rails/rails",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "8.0.0.beta1"
              },
              {
                "fixed": "8.0.4.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "72bc36fb47aa3a9b10149ecefc1f344d7b028d79"
            },
            {
              "fixed": "a79efed95797b196575a98845dc989e3106a9acb"
            }
          ],
          "repo": "https://github.com/rails/rails",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "7.2.3.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "ba76fca032a66f3716ca8a661c9ddb006acaf885"
            }
          ],
          "repo": "https://github.com/rails/rails",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-89vf-4333-qx8v"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33170.json"
  },
  "details": "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.",
  "id": "CVE-2026-33170",
  "modified": "2026-04-01T23:08:47.371205494Z",
  "published": "2026-03-23T23:09:48.923Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33170.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2db"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035beb"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rails/rails/releases/tag/v7.2.3.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rails/rails/releases/tag/v8.0.4.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rails/rails/releases/tag/v8.1.2.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/rails/rails/security/advisories/GHSA-89vf-4333-qx8v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33170"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Rails Active Support has a possible XSS vulnerability in SafeBuffer#%"
}