43/100 CVSS 7.5 🔴 CVE ANALYSISPublished: May 12, 2026

UltraJSON has a Memory Leak in ujson.dump() on Write Failure

### Summary 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. Code that uses `ujson.dumps()` rather than `ujson.dump()` or only JSON load/decode methods is unaff...

7.5

CVSS Score

LOW

Threat Level

Priority /100

TBD

Exploited ITW

Monitor

CISA Status

Sources

🔵

HIGH-PRIORITY SECURITY ADVISORY — Priority Score: 43/100

CVSS 7.5 LOW. SENTINEL APEX recommends immediate patch evaluation. Intelligence from 1 confirmed source(s).

📋 Executive Summary

⚡ Analyst Assessment — SENTINEL APEX v4.0

CYBERDUDEBIVASH SENTINEL APEX has confirmed a LOW-tier threat intelligence signal for CVE-2026-44660 affecting pip ujson. Composite threat score: 43/100. Intelligence corroborated across 1 source(s): github_advisories. CVSS base score: 7.5. Exploitation probability assessed as HIGH based on vulnerability characteristics.

Intelligence sources: github_advisories

⚠️ Business Impact Analysis

⚠️ pip ujson users face material security risk requiring immediate remediation

🔗 Attack Chain Analysis

Step-by-step attack chain based on observed TTPs and vulnerability characteristics:

#	Phase	Attacker Action	MITRE
1	Reconnaissance	Attacker identifies exposed ujson instances via Shodan, Censys, or targeted scanning	`TA0043`
2	Initial Access	Exploitation of CVE-2026-44660 in pip ujson	`T1190`
3	Persistence	Backdoor, scheduled task, or new admin account created for persistent access	`T1053`
4	Command & Control	Attacker establishes persistent C2 channel using HTTPS or DNS tunneling	`T1071`
5	Impact / Objectives	Intellectual property theft, espionage, cryptomining, or preparation for future attack stage	`T1657`

⚠ Deep Dive Analysis

This high-severity vulnerability in pip ujson (CVSS 7.5) represents a significant attack surface. SENTINEL APEX assesses exploitation to be technically feasible with moderate effort. Organizations running ujson in internet-facing or privileged positions face immediate risk.

SENTINEL APEX URGENCY: ELEVATED. Score: 43/100 LOW. Patch before exploitation activity begins.

🎯 MITRE ATT&CK Mapping

Category	Mapping
Primary Tactic	Initial Access
Primary Technique	T1190 — Exploit Public-Facing Application
Sub-Technique	T1203 — Exploitation for Client Execution
Weakness (CWE)	CWE-401
Intel Type	🔴 CVE ANALYSIS
Source(s)	github_advisories

🔴 CVE Reference

CVE ID	Reference	Score
CVE-2026-44660	NVD →	7.5
CVE-2026-44660	NVD →	7.5

🔍 Detection Rules — Sigma (SIEM)

Deploy to Splunk, Elastic, Microsoft Sentinel, or QRadar. SOC Pro subscribers receive pre-compiled SIEM-native query packs updated with each pipeline run.

Sigma YAMLtitle: CVE-2026-44660 Exploitation Attempt — pip ujson
id: 0e99a02617ffc357-ffc0
status: experimental
description: Detects exploitation of CVE-2026-44660 in pip ujson. Priority: LOW. Score: 43/100
author: CYBERDUDEBIVASH SENTINEL APEX v4.0 (bivash@cyberdudebivash.com)
date: 2026-05-12
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-44660
    - https://blog.cyberdudebivash.in/
tags:
    - attack.initial_access
    - attack.t1190
    - cve-2026-44660
    - cve-2026-44660
logsource:
    category: webserver
detection:
    keywords:
        - 'CVE-2026-44660'
        - 'CVE-2026-44660'
        - 'cve-2026-44660'
    condition: keywords
falsepositives:
    - Security scanners
level: medium

📡 Detection Rules — YARA (Endpoint)

Deploy to endpoint detection platforms. Enterprise subscribers receive tuned, FP-validated YARA rule packs.

YARArule CVE_2026_44660_Exploitation {
    meta:
        description = "Detects artifacts related to CVE-2026-44660 exploitation in pip ujson"
        author      = "CYBERDUDEBIVASH SENTINEL APEX v4.0"
        date        = "2026-05-12"
        severity    = "HIGH"
        cvss        = "7.5"
        priority    = "43/100"
        threat_level = "LOW"
        reference   = "https://nvd.nist.gov/vuln/detail/CVE-2026-44660"
    strings:
        $id_str  = "CVE-2026-44660" ascii nocase
        $product = "ujson" ascii nocase wide
    condition:
        any of them
}

🛡️ SOC Response Playbook

1IMMEDIATE (0-1hr): Identify all instances of ujson in your environment via CMDB/asset inventory
2IMMEDIATE (0-1hr): Apply vendor patch — no maintenance window exception for LOW threats
3IMMEDIATE (1-2hr): If no patch available: implement WAF rules, ACLs, or network-level compensating controls
4SHORT-TERM (2-4hr): Deploy Sigma detection rule to SIEM — validate alert generation in test environment
5SHORT-TERM (4-8hr): Review logs for exploitation indicators (anomalous ujson requests, error spikes)
6SHORT-TERM (8-24hr): Hunt for post-exploitation: new admin accounts, scheduled tasks, lateral movement
7MONITOR: Subscribe to pip security advisories for patch updates
8ONGOING: Track SENTINEL APEX intelligence feed for follow-on campaigns targeting ujson

📎 Intelligence References

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⚡ CYBERDUDEBIVASH SENTINEL APEX v4.0

Intelligence report generated by CYBERDUDEBIVASH SENTINEL APEX v4.0
Report ID: SENTINEL-CVE-2026-44660-2026-05-12 | Priority: 43/100 LOW | Sources: 1
© 2026 CYBERDUDEBIVASH PRIVATE LIMITED
Republication requires written attribution to CYBERDUDEBIVASH SENTINEL APEX

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