Type confusion in xmlParseReference (ctxt vs ctxt->userData in SAX callbacks). Introduced by commit e1153832 ("parser: Fix quadratic behavior when copying entities", 2024-01-07), first released in v2.

{
  "id": "6b28757cfde5335da547a98e687384711acdc4ff108d1aafd64e352cef099fdf",
  "url": "https://osv.dev/vulnerability/ECHO-778a-550a-1fd5",
  "method": "structured",
  "payload": {
    "kind": "withdrawal",
    "title": "Type confusion in xmlParseReference (ctxt vs ctxt->userData in SAX callbacks). Introduced by commit e1153832 (\"parser: Fix quadratic behavior when copying entities\", 2024-01-07), first released in v2.",
    "summary": "Type confusion in xmlParseReference (ctxt vs ctxt->userData in SAX callbacks). Introduced by commit e1153832 (\"parser: Fix quadratic behavior when copying entities\", 2024-01-07), first released in v2.13.0. Last unaffected release: v2.12.10. Debian trixie package is 2.12.7+dfsg+really2.9.14 (effectively v2.9.14) which predates the bug — all SAX callbacks in xmlParseReference already correctly pass ctxt->userData. Verified against the actual Debian source from salsa.debian.org. Not exploitable.",
    "evidence": "osv:ECHO-778a-550a-1fd5",
    "products": [
      {
        "name": {
          "value": "libxml2",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.12.7+dfsg+really2.9.14-2.1+deb13u2",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "libxml2-2.11.7",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.11.7+e1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "libxml2-2.15.3",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.15.3+e1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "libxml2-2.9.1",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.9.1+e1",
            "evidence": "/affected/3/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "ECHO-778a-550a-1fd5",
      "aliases": [
        "ECHO-778a-550a-1fd5"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.12.7+dfsg+really2.9.14-2.1+deb13u2"
                }
              ]
            }
          ],
          "package": {
            "name": "libxml2",
            "purl": "pkg:deb/echo/libxml2",
            "ecosystem": "Echo"
          },
          "database_specific": {
            "source": "https://advisory.echohq.com/osv/ECHO-778a-550a-1fd5.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "fixed": "2.11.7+e1"
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          ],
          "package": {
            "name": "libxml2-2.11.7",
            "purl": "pkg:deb/echo/libxml2-2.11.7",
            "ecosystem": "Echo"
          },
          "database_specific": {
            "source": "https://advisory.echohq.com/osv/ECHO-778a-550a-1fd5.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
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                  "introduced": "0"
                },
                {
                  "fixed": "2.15.3+e1"
                }
              ]
            }
          ],
          "package": {
            "name": "libxml2-2.15.3",
            "purl": "pkg:deb/echo/libxml2-2.15.3",
            "ecosystem": "Echo"
          },
          "database_specific": {
            "source": "https://advisory.echohq.com/osv/ECHO-778a-550a-1fd5.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.9.1+e1"
                }
              ]
            }
          ],
          "package": {
            "name": "libxml2-2.9.1",
            "purl": "pkg:deb/echo/libxml2-2.9.1",
            "ecosystem": "Echo"
          },
          "database_specific": {
            "source": "https://advisory.echohq.com/osv/ECHO-778a-550a-1fd5.json"
          }
        }
      ],
      "modified": "2026-10-21T12:45:09.408184240Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-6732"
      ],
      "references": [
        "https://advisory.echohq.com/cve/CVE-2026-6732"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-6732",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 393136,
  "published_at": "2026-04-24T21:00:06.809094+00:00"
}