Security advisory
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options. A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2019-25777
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 10:40 UTC · Revision 1
Source evidence
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options. A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
osv:CVE-2019-25777
Complete source record
{
"id": "df18061af7002283f34affaed1b9063221d7c97ad456aba2230905d3968dd3b5",
"url": "https://osv.dev/vulnerability/CVE-2019-25777",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2019-25777",
"summary": "YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options. A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.",
"evidence": "osv:CVE-2019-25777",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2019-25777",
"aliases": [
"CVE-2019-25777"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/ingydotnet/yaml-pm",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "b3c7869c21e7f71364394b817b55cae46fd74fa8"
},
{
"fixed": "bace96b5e6661d521c7c515c94a09e081c911fce"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.27_001"
}
],
"source": "DESCRIPTION"
},
{
"range": [
{
"fixed": "bace96b5e6661d521c7c515c94a09e081c911fce"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"1.27",
"1.26_001",
"1.26",
"1.25_002",
"1.25_001",
"1.25",
"1.24_002",
"1.24_001",
"1.24",
"1.23_003",
"old-yaml-pm-1.23",
"1.23",
"1.22",
"1.21",
"1.20_002",
"1.20_001",
"1.20",
"1.19_001",
"1.19",
"1.18_001",
"1.18",
"1.17",
"1.16_002",
"1.16_001",
"1.16",
"1.15",
"1.14",
"1.13",
"1.12",
"1.11",
"1.10",
"1.09",
"1.08",
"1.07",
"1.06",
"1.05",
"1.04",
"1.03",
"1.02",
"1.01",
"1.00",
"0.99",
"0.98",
"0.97",
"0.96",
"0.95",
"0.94",
"0.93",
"v0.92",
"v0.91",
"v0.90",
"v0.89",
"0.88",
"0.87",
"0.86",
"0.85",
"0.84",
"0.83",
"0.82",
"0.81",
"0.80",
"0.79",
"0.78",
"0.74",
"0.77",
"0.76",
"0.75",
"0.73",
"0.72",
"0.71",
"0.70",
"0.68",
"0.67",
"0.66",
"0.65",
"0.64",
"0.63",
"0.62",
"0.61",
"0.60",
"0.58",
"0.57",
"0.56",
"0.55",
"0.54",
"0.53",
"0.52",
"0.51",
"0.50",
"0.49_70",
"0.39",
"0.38",
"0.37",
"0.36",
"0.49_01",
"0.35",
"0.30",
"0.26",
"0.25"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-25777.json"
}
}
],
"modified": "2026-10-20T10:50:54.913556673Z",
"provider": "osv",
"references": [
"https://metacpan.org/release/TINITA/YAML-1.28/changes",
"https://github.com/ingydotnet/yaml-pm/issues/212",
"https://github.com/ingydotnet/yaml-pm/commit/bace96b5e6661d521c7c515c94a09e081c911fce.patch"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2019-25777",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 382348,
"published_at": "2026-10-05T07:16:29.557+00:00"
}