CVE-2026-32874

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-32874
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-32874.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-32874
Aliases
Downstream
Related
Published
2026-03-20T01:31:30.207Z
Modified
2026-04-02T13:26:21.670393Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
UltraJSON has a Memory Leak parsing large integers allows DoS
Details

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.getintmaxstrdigits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32874.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-401"
    ]
}
References

Affected packages

Git / github.com/ultrajson/ultrajson

Affected ranges

Type
GIT
Repo
https://github.com/ultrajson/ultrajson
Events
Introduced
9c20de0f77b391093967e25d01fb48671104b15b
Fixed
4baeb950df780092bd3c89fc702a868e99a3a1d2

Affected versions

5.*
5.10.0
5.11.0
5.4.0
5.5.0
5.6.0
5.7.0
5.8.0
5.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-32874.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "signature_type": "Function",
        "signature_version": "v1",
        "digest": {
            "function_hash": "143310115266596760550047779091978638434",
            "length": 208.0
        },
        "source": "https://github.com/ultrajson/ultrajson/commit/4baeb950df780092bd3c89fc702a868e99a3a1d2",
        "id": "CVE-2026-32874-2eef43e2",
        "target": {
            "file": "src/ujson/python/JSONtoObj.c",
            "function": "Object_newIntegerFromString"
        }
    },
    {
        "deprecated": false,
        "signature_type": "Line",
        "signature_version": "v1",
        "digest": {
            "line_hashes": [
                "212837420080635112568003154091060587471",
                "241759147848847498980092687999678446212",
                "194454409089925620071785617117145682182",
                "339550761962974907817774276192931794922"
            ],
            "threshold": 0.9
        },
        "source": "https://github.com/ultrajson/ultrajson/commit/4baeb950df780092bd3c89fc702a868e99a3a1d2",
        "id": "CVE-2026-32874-a1544599",
        "target": {
            "file": "src/ujson/python/JSONtoObj.c"
        }
    }
]