Security advisory

{
  "id": "3e9bc80993cc88ab90c6a98eabd4f268f09f9f9d25f10ec380c9391efb98818e",
  "url": "https://osv.dev/vulnerability/CVE-2021-28906",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-28906",
    "summary": "In function read_yin_leaf() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a crash.",
    "evidence": "osv:CVE-2021-28906",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-28906",
      "aliases": [
        "CVE-2021-28906"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cesnet/libyang",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "8e9f87949974c7b2c6dc5e830c0e78e4160fbc50"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:cesnet:libyang:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.0.225"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.0.225",
            "v1.0.167",
            "v1.0.130",
            "v1.0.109",
            "v1.0-r5",
            "v1.0-r4",
            "v1.0-r3",
            "v1.0-r2",
            "v1.0-r1",
            "v0.16-r2",
            "v0.16-r1",
            "v0.15-r1",
            "v0.14-r1",
            "v0.13-r2",
            "v0.12-r2",
            "v0.12-r1",
            "v0.11-r2",
            "v0.11-r1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-28906.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:36.498489352Z",
      "provider": "osv",
      "references": [
        "https://security.gentoo.org/glsa/202107-54",
        "https://github.com/CESNET/libyang/issues/1455"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-28906",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385717,
  "published_at": "2021-05-20T19:15:07.747+00:00"
}