DEBIAN-CVE-2026-32875
UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.10 through 5.11.0 are vulnerable to buffer overflow or infinite loop through large indent handling. ujson.dumps() crashes the Python interpreter (segmentation fault) when the product of the indent parameter and the nested depth of the input exceeds INT32_MAX. It can also get stuck in an infinite loop if the indent is a large negative number. Both are caused by an integer overflow/underflow whilst calculating how much memory to reserve for indentation. And both can be used to achieve denial of service. To be vulnerable, a service must call ujson.dump()/ujson.dumps()/ujson.encode() whilst giving untrusted users control over the indent parameter and not restrict that indentation to reasonably small non-negative values. A service may also be vulnerable to the infinite loop if it uses a fixed negative indent. An underflow always occurs for any negative indent when the input data is at least one level nested but, for small negative indents, the underflow is usually accidentally rectified by another overflow. This issue has been fixed in version 5.12.0.
DEBIAN-CVE-2026-32875
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-2026-32875
ujson
Source reference: /affected/0/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/0/versions5.11.0-1Source reference:
/affected/0/versions5.11.0-2Source reference:
/affected/0/versions5.11.0-3Source reference:
/affected/0/versions5.13.0-1Source reference:
/affected/0/versions5.7.0-1Source reference:
/affected/0/versions5.8.0-1Source reference:
/affected/0/versions5.9.0-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ujson
Source reference: /affected/1/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/1/versions5.11.0-1Source reference:
/affected/1/versions5.11.0-2Source reference:
/affected/1/versions5.11.0-3Source reference:
/affected/1/versions5.13.0-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ujson
Source reference: /affected/2/package/name
- Affected versions
- 5.10.0-1
Source reference:
/affected/2/versions5.11.0-1Source reference:
/affected/2/versions5.11.0-2Source reference:
/affected/2/versions5.11.0-3Source reference:
/affected/2/versions - Fixed versions
- 5.13.0-1
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": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"5.10.0-1",
"5.11.0-1",
"5.11.0-2",
"5.11.0-3",
"5.13.0-1",
"5.7.0-1",
"5.8.0-1",
"5.9.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-32875.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"5.10.0-1",
"5.11.0-1",
"5.11.0-2",
"5.11.0-3",
"5.13.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-32875.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.13.0-1"
}
]
}
],
"package": {
"name": "ujson",
"purl": "pkg:deb/debian/ujson?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"5.10.0-1",
"5.11.0-1",
"5.11.0-2",
"5.11.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-32875.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57519 · Revision 1
- Added to Heist Feed
- Publisher date