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Fencer Vulns
high 7.5

CVE-2025-67221 json

orjson does not limit recursion for deeply nested JSON documents

published 2026-01-22 9 mo ago modified 2026-09-10 1 mo ago also GHSA-hx9q-6w63-j58v , PYSEC-2026-107 , EUVD-2026-3806

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

The orjson.dumps function in orjson thru 3.11.4 does not limit recursion for deeply nested JSON documents.

Patch / fix

  • pypi orjson 3.11.5, 3.11.6
  • python-orjson SLES for SAP applications 16.0, SLES 16.0 3.10.15-160000.3.1

suse advisories SUSE-SU-2026:20920-1

  • python-orjson openSUSE Leap 16.0 3.10.15-160000.3.1
  • python-orjson openSUSE Tumbleweed 3.11.5-1.1

opensuse advisories openSUSE-SU-2026:20407-1openSUSE-SU-2026:10103-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-67221 updated cvss 5.5

orjson: orjson: Denial of Service due to unbounded recursion with deeply nested JSON documents

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform/ee-minimal-rhel9, ansible-automation-platform-26/mcp-tools-rhel9, ansible-automation-platform-24/de-minimal-rhel8, ansible-automation-platform-24/de-minimal-rhel9, ansible-automation-platform-24/ee-minimal-rhel8, +31 more Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/disk-image-cuda-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-caikit-nlp-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-llama-stack-core-rhel9, rhoai/odh-kserve-controller-rhel9, rhoai/odh-caikit-tgis-serving-rhel9, +2 more
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kpatsakis/orjson_vulnerability referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi orjson
<3.11.6
<3.11.5
3.11.6
3.11.5

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.