---
cve: "CVE-2026-44660"
severity: "HIGH"
cvss: 8.7
epss: "0.4%"
vendor: "ultrajson"
kev: false
exploited: false
published: "2026-05-27 21:16:17"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T08:00:35+02:00"
---

# CVE-2026-44660

> 8.7 HIGH · 🧪 PoC

## Beschreibung

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to 5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the full size of the serialized payload. This vulnerability is fixed in 5.12.1.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 7d9036f4896256ac772fdb45d27d45463efe59cb (Commit)
- 82af1d0ac01d09aa40c887b460d44b9d9f4bccd9 (Commit)

## Referenzen

- <https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg>
- <https://github.com/ultrajson/ultrajson/commit/82af1d0ac01d09aa40c887b460d44b9d9f4bccd9>
- <https://github.com/ultrajson/ultrajson/releases/tag/5.12.1>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-44660) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_