Skip to content
Heist/ feed
Back to feed
HighFix available

libidn2 — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2019-12290

GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.

Products
libidn2
Affected versions
Not specified
Fixed versions
2.2.0-1
CVEs
CVE-2019-12290
Confirmed fixed CVEs
Not specified
Updated in this feed
30 Oct 2026, 14:21 UTC · Revision 1

Source evidence

DEBIAN-CVE-2019-12290

core-osv · Original source

Published 22 Oct 2019, 16:15 UTC

GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.

osv:DEBIAN-CVE-2019-12290

libidn2

Fixed versions: 2.2.0-1

libidn2

Fixed versions: 2.2.0-1

libidn2

Fixed versions: 2.2.0-1

Complete source record
{
  "id": "151f54636a1c6591c64f8ad804656fd212568d734bd2b94b71befd8efd89cc8c",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2019-12290",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2019-12290",
    "summary": "GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.",
    "evidence": "osv:DEBIAN-CVE-2019-12290",
    "products": [
      {
        "name": {
          "value": "libidn2",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.2.0-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "libidn2",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.2.0-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "libidn2",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.2.0-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2019-12290",
      "aliases": [
        "DEBIAN-CVE-2019-12290"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.2.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "libidn2",
            "purl": "pkg:deb/debian/libidn2?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-12290.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.2.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "libidn2",
            "purl": "pkg:deb/debian/libidn2?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-12290.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.2.0-1"
                }
              ]
            }
          ],
          "package": {
            "name": "libidn2",
            "purl": "pkg:deb/debian/libidn2?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2019-12290.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-15T07:47:25.294669139Z",
      "provider": "osv",
      "upstream": [
        "CVE-2019-12290"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2019-12290"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2019-12290",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 322117,
  "published_at": "2019-10-22T16:15:10.877+00:00"
}