Security advisory

{
  "id": "1ca2f20f8c104057671d02eb02859cffa8305532b22dd27ccccb709f04a18ef3",
  "url": "https://osv.dev/vulnerability/CVE-2021-3831",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-3831",
    "summary": "gnuboard5 is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')",
    "evidence": "osv:CVE-2021-3831",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-3831",
      "aliases": [
        "CVE-2021-3831"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/gnuboard/gnuboard5",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "a73967dd9a4218b7a75d58814fcc56c1290862bb"
                },
                {
                  "fixed": "2e81619ea87bc9c0b4a073d8df3c7693a6fdbf0d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:gnuboard:gnuboard5:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.4.20"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "2e81619ea87bc9c0b4a073d8df3c7693a6fdbf0d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v5.4.19",
            "v5.4.18",
            "v5.4.18.1",
            "v5.4.17",
            "v5.4.16",
            "v5.4.15.1",
            "v5.4.15",
            "v5.4.14",
            "v5.4.13.1",
            "v5.4.13",
            "v5.4.12",
            "v5.4.11",
            "v5.4.10",
            "v5.4.9",
            "v5.4.8",
            "v5.4.7",
            "5.4.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-3831.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:51.527221048Z",
      "provider": "osv",
      "references": [
        "https://github.com/gnuboard/gnuboard5/commit/2e81619ea87bc9c0b4a073d8df3c7693a6fdbf0d",
        "https://huntr.dev/bounties/25775287-88cd-4f00-b978-692d627dff04"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-3831",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386291,
  "published_at": "2021-12-14T11:15:07.417+00:00"
}