2026年7月8日の
セキュリティ情報

Subject: [Security Alert] Warning Against Installing Unknown Apps

Dear employees,

It has been reported that Android spyware is being distributed through social media platforms like Telegram via deceptive links.

To protect your device and company data, please follow these steps:
1. Do not click on suspicious links or install apps from unknown sources (SMS, email, or social media).
2. Only install applications from official sources, such as the Google Play Store.
3. If you suspect you have installed a malicious app, please contact the IT security team immediately.

Deadline: Immediate

Subject: [Security Advisory] Langflow CVE-2026-55255 Mitigation

Dear IT/Security Team,

We are sharing information regarding a critical vulnerability in Langflow.

■ Overview
An authorization bypass vulnerability (CVE-2026-55255) has been identified in the Langflow API endpoint. With a CVSS v3.1 score of 8.4, this flaw allows an authenticated attacker to access and utilize workflows of other users. Active exploitation in the wild has been detected.

■ Scope
- Product: Langflow
- Affected Versions: Versions prior to the security patch

■ Mitigation Steps
1. Verify the current version of Langflow deployed in your environment.
2. Update Langflow to the latest patched version provided by the vendor immediately.

■ Reference
- CVE-2026-55255

Priority: High
Deadline: Immediate

Subject: [Security Alert] Vulnerabilities in Dell PowerProtect Data Domain

Dear IT/Security Team,

We are sharing critical vulnerability information regarding Dell PowerProtect Data Domain.

■ Overview
Dell has identified 143 vulnerabilities in PowerProtect Data Domain and its third-party components. Specifically, CVE-2026-53481 and CVE-2026-53483 have been assigned a CVSS v3.1 score of 9.8 (Critical), as they could allow an unauthenticated remote attacker to gain full system control.

■ Scope
- Affected Product: Dell PowerProtect Data Domain

■ Action Required
1. Review Dell Security Advisory DSA-2026-278 to determine if your environment is affected.
2. Apply the latest security updates immediately.

■ Reference
- Dell DSA-2026-278: Security Update for Dell PowerProtect Data Domain Multiple Vulnerabilities

Priority: High
Deadline: Immediate

Subject: [Security Advisory] Linux Kernel Vulnerability CVE-2026-43499 (GhostLock)

Dear IT/Security Team,

We are sharing information regarding a critical vulnerability in the Linux kernel known as "GhostLock."

■ Overview
CVE-2026-43499 is a long-standing flaw in the kernel's task cleanup mechanism. It allows a local user to escalate privileges to root and escape containers. Public exploit code is available, making this a high-risk issue.

■ Scope
- Most mainstream Linux distributions shipped since 2011.
- Containerized environments (risk of container escape).

■ Mitigation Steps
1. Identify all Linux servers and container hosts in the environment.
2. Apply the latest kernel security patches provided by your distribution vendor and reboot the systems.

■ Reference
- CVE-2026-43499

Priority: High
Deadline: Immediate

Subject: [Security Advisory] Arbitrary File Upload in Joomla Page Builder CK (CVE-2026-56290)

Dear IT/Security Team,

We are sharing information regarding a critical vulnerability in Joomla Page Builder CK.

■ Overview
An unauthenticated arbitrary file upload vulnerability (CVE-2026-56290) exists in the `fonts.save` task of Page Builder CK. This allows an attacker to upload a PHP shell to the webroot and achieve Remote Code Execution (RCE). The CSRF token required for the request is publicly accessible on the homepage.

■ Scope
- Product: Joomla Page Builder CK (com_pagebuilderck)
- Affected Versions: <= 3.5.10

■ Remediation
1. Identify all instances of Joomla Page Builder CK in your environment.
2. Update the extension to version 3.6.0 or later immediately.

■ Reference
- CVE-2026-56290
- Vendor: https://www.joomlack.fr/

Priority: High
Deadline: Immediate