CVE catalog
CVE-2026-44660
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 exceptio
- Severity
- High · CVSS 8.7
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.42% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | ujson | sid | 5.13.0-1 | fixed |
| Debian | ujson | forky | 5.13.0-1 | fixed |
| Debian | ujson | trixie | 5.10.0-1 | vulnerable |
| Debian | ujson | bookworm | 5.7.0-1 | vulnerable |
| Cpe | ujson | Not reported | Not reported | vulnerable |
| Cpe | ultrajson | Not reported | 5.12.1 | fixed |
| Suse | python-ujson | linux enterprise server 16.0 | 5.10.0-160000.3.1 | fixed |
| Suse | python-ujson | linux enterprise server for sap applications 16.0 | 5.10.0-160000.3.1 | fixed |
| Suse | python-ujson | linux enterprise server 16.0 | 5.10.0-160000.3.1 | fixed |
| Suse | python-ujson | linux enterprise server for sap applications 16.0 | 5.10.0-160000.3.1 | fixed |
| Suse | python-ujson | linux enterprise module for development tools 15 sp7 | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise module for package hub 15 sp7 | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise high performance computing 15 sp4-espos | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise high performance computing 15 sp4-ltss | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise high performance computing 15 sp5-espos | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise high performance computing 15 sp5-ltss | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server 15 sp4-ltss | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server 15 sp5-ltss | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server 15 sp6-ltss | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server for sap applications 15 sp4 | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server for sap applications 15 sp5 | 1.35-150100.3.13.1 | fixed |
| Suse | python-ujson | linux enterprise server for sap applications 15 sp6 | 1.35-150100.3.13.1 | fixed |
| Opensuse | python-ujson | leap 16.0 | 5.10.0-160000.3.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | ujson | source | sid | 5.13.0-1 | not yet assigned | Not reported | [1138258] |
| Debian | ujson | source | forky | 5.13.0-1 | not yet assigned | Not reported | [1138258] |
| Debian | ujson | source | trixie | (unfixed) | not yet assigned | Not reported | [1138258] |
| Debian | ujson | source | bookworm | (unfixed) | not yet assigned | Not reported | [1138258] |
| Cpe | ultrajson | cpe | Not reported | 5.12.1 | Not reported | Not reported | Not reported |
| Suse | python-ujson | rpm | linux enterprise server 16.0 | 5.10.0-160000.3.1 | Not reported | SUSE-SU-2026:23136-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server for sap applications 16.0 | 5.10.0-160000.3.1 | Not reported | SUSE-SU-2026:23136-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server 16.0 | 5.10.0-160000.3.1 | Not reported | SUSE-SU-2026:23114-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server for sap applications 16.0 | 5.10.0-160000.3.1 | Not reported | SUSE-SU-2026:23114-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise module for development tools 15 sp7 | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise module for package hub 15 sp7 | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise high performance computing 15 sp4-espos | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise high performance computing 15 sp4-ltss | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise high performance computing 15 sp5-espos | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise high performance computing 15 sp5-ltss | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server 15 sp4-ltss | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server 15 sp5-ltss | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server 15 sp6-ltss | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server for sap applications 15 sp4 | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server for sap applications 15 sp5 | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Suse | python-ujson | rpm | linux enterprise server for sap applications 15 sp6 | 1.35-150100.3.13.1 | Not reported | SUSE-SU-2026:3539-1 | Not reported |
| Opensuse | python-ujson | rpm | leap 16.0 | 5.10.0-160000.3.1 | Not reported | OPENSUSE-SU-2026:21518-1 | Not reported |
Notes
[trixie] ujson: Minor issue [bookworm] ujson: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-ujson]Affected
Source package: [ujson]
Details (2)
5.7.0-1· amd64 · bookwormAffected
nvd · ujson · debian · bookworm; nvd · ujson · debian · 12
5.7.0-1· arm64 · bookwormAffected
nvd · ujson · debian · bookworm; nvd · ujson · debian · 12
[Debian 13 (Trixie)]
- [python3-ujson]Affected
Source package: [ujson]
Details (2)
5.10.0-1+b4· amd64 · trixieAffected
nvd · ujson · debian · 13
5.10.0-1+b4· arm64 · trixieAffected
nvd · ujson · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_21518-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-44660]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-44660]
- [https://osv.dev/vulnerability/SUSE-SU-2026:23114-1]
- [https://osv.dev/vulnerability/SUSE-SU-2026:23136-1]
- [https://osv.dev/vulnerability/SUSE-SU-2026:3539-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:21518-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-44660]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44660.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]