DEBIAN-CVE-2026-33228
flatted is a circular JSON parser. Prior to version 3.4.2, the parse() function in flatted can use attacker-controlled string values from the parsed JSON as direct array index keys, without validating that they are numeric. Since the internal input buffer is a JavaScript Array, accessing it with the key "__proto__" returns Array.prototype via the inherited getter. This object is then treated as a legitimate parsed value and assigned as a property of the output object, effectively leaking a live reference to Array.prototype to the consumer. Any code that subsequently writes to that property will pollute the global prototype. This issue has been patched in version 3.4.2.
DEBIAN-CVE-2026-33228
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-2026-33228
node-flatted
Source reference: /affected/0/package/name
- Affected versions
- 3.2.7~ds-1
Source reference:
/affected/0/versions3.2.7~ds-1+deb12u1Source reference:
/affected/0/versions3.4.1~ds-1Source reference:
/affected/0/versions3.4.2~ds-1Source reference:
/affected/0/versions3.4.4~ds-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
node-flatted
Source reference: /affected/1/package/name
- Affected versions
- 3.2.7~ds-1
Source reference:
/affected/1/versions - Fixed versions
- 3.2.7~ds-1+deb13u1
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
node-flatted
Source reference: /affected/2/package/name
- Affected versions
- 3.2.7~ds-1
Source reference:
/affected/2/versions3.4.1~ds-1Source reference:
/affected/2/versions - Fixed versions
- 3.4.2~ds-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-flatted",
"purl": "pkg:deb/debian/node-flatted?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"3.2.7~ds-1",
"3.2.7~ds-1+deb12u1",
"3.4.1~ds-1",
"3.4.2~ds-1",
"3.4.4~ds-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33228.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.2.7~ds-1+deb13u1"
}
]
}
],
"package": {
"name": "node-flatted",
"purl": "pkg:deb/debian/node-flatted?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"3.2.7~ds-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33228.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.4.2~ds-1"
}
]
}
],
"package": {
"name": "node-flatted",
"purl": "pkg:deb/debian/node-flatted?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"3.2.7~ds-1",
"3.4.1~ds-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33228.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56837 · Revision 1
- Added to Heist Feed
- Publisher date