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DEBIAN-CVE-2026-4177

Type: advisorySource: OSV1 source record

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data. A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.

Announced Source revision 1
Original source ↗

DEBIAN-CVE-2026-4177

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-4177

libyaml-syck-perl

Source reference: /affected/0/package/name

Affected versions
1.34-2

Source reference: /affected/0/versions

1.34-2+deb12u1

Source reference: /affected/0/versions

Fixed versions
1.34-2+deb12u2

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

libyaml-syck-perl

Source reference: /affected/1/package/name

Affected versions
1.34-2

Source reference: /affected/1/versions

1.34-2+deb13u1

Source reference: /affected/1/versions

Fixed versions
1.34-2+deb13u2

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

libyaml-syck-perl

Source reference: /affected/2/package/name

Affected versions
1.34-2

Source reference: /affected/2/versions

1.34-3

Source reference: /affected/2/versions

1.34-4

Source reference: /affected/2/versions

1.36-1

Source reference: /affected/2/versions

Fixed versions
1.36-2

Source reference: /affected/2/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.34-2+deb12u2"
          }
        ]
      }
    ],
    "package": {
      "name": "libyaml-syck-perl",
      "purl": "pkg:deb/debian/libyaml-syck-perl?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "1.34-2",
      "1.34-2+deb12u1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-4177.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.34-2+deb13u2"
          }
        ]
      }
    ],
    "package": {
      "name": "libyaml-syck-perl",
      "purl": "pkg:deb/debian/libyaml-syck-perl?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "1.34-2",
      "1.34-2+deb13u1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-4177.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.36-2"
          }
        ]
      }
    ],
    "package": {
      "name": "libyaml-syck-perl",
      "purl": "pkg:deb/debian/libyaml-syck-perl?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "1.34-2",
      "1.34-3",
      "1.34-4",
      "1.36-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-4177.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event
#56459 · Revision 1
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Publisher date
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