DEBIAN-CVE-2026-84375
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 & v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1.
DEBIAN-CVE-2026-84375
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-2026-84375
node-js-yaml
Source reference: /affected/0/package/name
- Affected versions
- 4.1.0+dfsg+~4.0.5-7
Source reference:
/affected/0/versions4.1.1+dfsg+~4.0.9-1Source reference:
/affected/0/versions4.2.0+~4.0.9-1Source reference:
/affected/0/versions4.2.0+~4.0.9-2Source reference:
/affected/0/versions4.3.2+~4.0.9-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
node-js-yaml
Source reference: /affected/1/package/name
- Affected versions
- 4.1.0+dfsg+~4.0.5-7
Source reference:
/affected/1/versions4.1.1+dfsg+~4.0.9-1Source reference:
/affected/1/versions4.2.0+~4.0.9-1Source reference:
/affected/1/versions4.2.0+~4.0.9-2Source reference:
/affected/1/versions4.3.2+~4.0.9-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
node-js-yaml
Source reference: /affected/2/package/name
- Affected versions
- 4.1.0+dfsg+~4.0.5-7
Source reference:
/affected/2/versions4.1.1+dfsg+~4.0.9-1Source reference:
/affected/2/versions4.2.0+~4.0.9-1Source reference:
/affected/2/versions4.2.0+~4.0.9-2Source reference:
/affected/2/versions - Fixed versions
- 4.3.2+~4.0.9-1
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"
}
]
}
],
"package": {
"name": "node-js-yaml",
"purl": "pkg:deb/debian/node-js-yaml?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"4.1.0+dfsg+~4.0.5-7",
"4.1.1+dfsg+~4.0.9-1",
"4.2.0+~4.0.9-1",
"4.2.0+~4.0.9-2",
"4.3.2+~4.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84375.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "node-js-yaml",
"purl": "pkg:deb/debian/node-js-yaml?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.1.0+dfsg+~4.0.5-7",
"4.1.1+dfsg+~4.0.9-1",
"4.2.0+~4.0.9-1",
"4.2.0+~4.0.9-2",
"4.3.2+~4.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84375.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.3.2+~4.0.9-1"
}
]
}
],
"package": {
"name": "node-js-yaml",
"purl": "pkg:deb/debian/node-js-yaml?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"4.1.0+dfsg+~4.0.5-7",
"4.1.1+dfsg+~4.0.9-1",
"4.2.0+~4.0.9-1",
"4.2.0+~4.0.9-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-84375.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #25813 · Revision 1
- Added to Heist Feed
- Publisher date