CVE-2025-67221

HIGH

orjson < 3.11.4 - Denial of Service via Deeply Nested JSON Documents

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2025-67221. PoCs published by kpatsakis.

AI-analyzed exploit summary This repository contains a working proof-of-concept for CVE-2025-67221, a denial-of-service vulnerability in orjson versions ≤ 3.11.4 due to uncontrolled recursion in the `orjson.dumps()` function. The PoC demonstrates a crash by serializing a deeply nested data structure.

Description

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

Exploits (1)

nomisec WORKING POC 1 stars
by kpatsakis · poc
https://github.com/kpatsakis/CVE-2025-67221

This repository contains a working proof-of-concept for CVE-2025-67221, a denial-of-service vulnerability in orjson versions ≤ 3.11.4 due to uncontrolled recursion in the `orjson.dumps()` function. The PoC demonstrates a crash by serializing a deeply nested data structure.

Classification
Working Poc 100%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: orjson ≤ 3.11.4
No auth needed
Prerequisites: Ability to cause the target application to serialize attacker-controlled nested data
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (2)

Core 2
Core References

Scores

CVSS v3 7.5
EPSS 0.0003
EPSS Percentile 8.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-770
Status published
Products (2)
ijl/orjson < 3.11.4
pypi/orjson 0 - 3.11.6PyPI
Published Jan 22, 2026
Tracked Since Feb 18, 2026