45/100 CVSS 7.5 🔴 CVE ANALYSISPublished: June 12, 2026

TYPO3 CMS has Broken Access Control in its Media Module

### Problem Backend users with file download permissions were able to download files from the fallback storage of the file abstraction layer (FAL) via the Media Module. Since the fallback storage resolves paths relative to the server's document root, this could expose sensitive files such as log files. ### Solution Update to TYPO3 versions 11.5.51 ...

7.5

CVSS Score

MEDIUM

Threat Level

Priority /100

TBD

Exploited ITW

Monitor

CISA Status

Sources

🔵

HIGH-PRIORITY SECURITY ADVISORY — Priority Score: 45/100

CVSS 7.5 MEDIUM. 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 MEDIUM-tier threat intelligence signal for CVE-2026-49742 affecting composer typo3/cms-core. Composite threat score: 45/100. 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

⚠️ Remote code execution — full server takeover without authentication possible

🔗 Attack Chain Analysis

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

#	Phase	Attacker Action	MITRE
1	Reconnaissance	Attacker identifies exposed typo3/cms-core instances via Shodan, Censys, or targeted scanning	`TA0043`
2	Initial Access	Exploitation of CVE-2026-49742 in composer typo3/cms-core	`T1190`
3	Execution	Remote code execution achieved — attacker runs arbitrary commands on target system	`T1203`
4	Persistence	Backdoor, scheduled task, or new admin account created for persistent access	`T1053`
5	Command & Control	Attacker establishes persistent C2 channel using HTTPS or DNS tunneling	`T1071`
6	Impact / Objectives	Intellectual property theft, espionage, cryptomining, or preparation for future attack stage	`T1657`

⚠ Deep Dive Analysis

This high-severity vulnerability in composer typo3/cms-core (CVSS 7.5) represents a significant attack surface. SENTINEL APEX assesses exploitation to be technically feasible with moderate effort. Organizations running typo3/cms-core in internet-facing or privileged positions face immediate risk.

SENTINEL APEX URGENCY: ELEVATED. Score: 45/100 MEDIUM. Patch before exploitation activity begins.

🎯 MITRE ATT&CK Mapping

Category	Mapping
Primary Tactic	Execution
Primary Technique	T1203 — Exploitation for Client Execution
Sub-Technique	T1059 — Command & Scripting Interpreter
Weakness (CWE)	CWE-22
Intel Type	🔴 CVE ANALYSIS
Source(s)	github_advisories

🔴 CVE Reference

CVE ID	Reference	Score
CVE-2026-49742	NVD →	7.5
CVE-2026-49742	NVD →	7.5

🏷️ Indicators of Compromise — Enriched IOC Feed

Normalized IOCs with confidence scoring. Block immediately across all enforcement points. SOC Pro subscribers receive enriched IOC bundles with full attribution and STIX/TAXII feeds.

Indicator Value	Type	Confidence	First Seen
https://typo3.org/security/advisory/typo3-core-sa-2026-013)	url	82%	2026-06-12
typo3.org	domain	75%	2026-06-12

🔍 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-2026-49742 Exploitation Attempt — composer typo3/cms-core
id: d339c98293f76f9c-8ae4
status: experimental
description: Detects exploitation of CVE-2026-49742 in composer typo3/cms-core. Priority: MEDIUM. Score: 45/100
author: CYBERDUDEBIVASH SENTINEL APEX v4.0 (bivash@cyberdudebivash.com)
date: 2026-06-12
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2026-49742
    - https://blog.cyberdudebivash.in/
tags:
    - attack.initial_access
    - attack.t1190
    - cve-2026-49742
    - cve-2026-49742
logsource:
    category: webserver
detection:
    keywords:
        - 'CVE-2026-49742'
        - 'CVE-2026-49742'
        - 'cve-2026-49742'
    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_49742_Exploitation {
    meta:
        description = "Detects artifacts related to CVE-2026-49742 exploitation in composer typo3/cms-core"
        author      = "CYBERDUDEBIVASH SENTINEL APEX v4.0"
        date        = "2026-06-12"
        severity    = "HIGH"
        cvss        = "7.5"
        priority    = "45/100"
        threat_level = "MEDIUM"
        reference   = "https://nvd.nist.gov/vuln/detail/CVE-2026-49742"
    strings:
        $id_str  = "CVE-2026-49742" ascii nocase
        $product = "typo3_cms_core" ascii nocase wide
    condition:
        any of them
}

🛡️ SOC Response Playbook

1IMMEDIATE (0-1hr): Identify all instances of typo3/cms-core in your environment via CMDB/asset inventory
2IMMEDIATE: Block all 2 IOCs in this report at firewall, proxy, DNS, and EDR simultaneously
3IMMEDIATE (0-1hr): Apply vendor patch — no maintenance window exception for MEDIUM threats
4IMMEDIATE (1-2hr): If no patch available: implement WAF rules, ACLs, or network-level compensating controls
5SHORT-TERM (2-4hr): Deploy Sigma detection rule to SIEM — validate alert generation in test environment
6SHORT-TERM (4-8hr): Review logs for exploitation indicators (anomalous typo3/cms-core requests, error spikes)
7SHORT-TERM (8-24hr): Hunt for post-exploitation: new admin accounts, scheduled tasks, lateral movement
8MONITOR: Subscribe to composer security advisories for patch updates
9ONGOING: Track SENTINEL APEX intelligence feed for follow-on campaigns targeting typo3/cms-core

📎 Intelligence References

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⚡ CYBERDUDEBIVASH SENTINEL APEX v4.0

Intelligence report generated by CYBERDUDEBIVASH SENTINEL APEX v4.0
Report ID: SENTINEL-CVE-2026-49742-2026-06-12 | Priority: 45/100 MEDIUM | Sources: 1
© 2026 CYBERDUDEBIVASH PRIVATE LIMITED
Republication requires written attribution to CYBERDUDEBIVASH SENTINEL APEX

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