Critical Oracle APEX Flaw Allows Unauthenticated Remote Takeover
A severe vulnerability in Oracle Application Express enables attackers to seize full control of the application without credentials via HTTPS.
Key points
- CVE-2026-101521 carries a CVSS 9.8 score, marking it as critical severity.
- The flaw affects Oracle APEX versions 24.1.0 through 24.1.21, 24.2.0 through 24.2.20, and 26.1.0 through 26.1.4.
- Attackers require only network access via HTTPS to exploit the weakness without authentication.
The National Vulnerability Database records a critical security flaw in Oracle Application Express that allows unauthenticated attackers to take over the system. Identified as CVE-2026-101521, the vulnerability enables remote compromise via standard HTTPS connections without requiring any user credentials or interaction.
This weakness affects multiple supported release streams of the software. According to the NVD record, the issue is present in Oracle APEX versions 24.1.0 through 24.1.21, 24.2.0 through 24.2.20, and 26.1.0 through 26.1.4. The flaw is rated with a CVSS 3.1 Base Score of 9.8, indicating a critical severity level for confidentiality, integrity, and availability impacts.
Technical Context and Severity
The vulnerability is classified as easily exploitable, allowing an attacker with network access to compromise the Oracle APEX instance entirely. Successful exploitation results in a complete takeover of the application. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H reflects the low complexity and remote nature of the attack.
Because no user interaction is required and no privileges are needed, the attack surface is broad for any exposed instance. The high scores for confidentiality, integrity, and availability suggest that an attacker could read, modify, or disrupt all data and services hosted within the vulnerable APEX environment.
Who Is Affected
Organizations running specific versions of Oracle APEX are directly at risk. The NVD record lists three distinct version ranges that contain this flaw. Administrators managing instances of version 24.1.0 up to 24.1.21 must verify their exposure.
Similarly, those operating version 24.2.0 through 24.2.20 are affected by this critical weakness. The most recent supported stream, version 26.1.0 through 26.1.4, also contains the vulnerability. Any deployment within these version bounds is susceptible to unauthorized access if reachable via HTTPS.
The vulnerability is located in the General component of Oracle APEX. This broad categorization suggests the flaw may impact core functionalities rather than a specific optional module, increasing the potential impact on standard deployments.
What should you do?
No confirmed patch or fix has been mentioned in the available source material for CVE-2026-101521. Security teams should immediately inventory their Oracle APEX environments to determine if they are running any of the affected version ranges listed in the NVD record.
WHAT TO DO
- Audit all Oracle APEX instances to identify if they fall within the affected version ranges 24.1.0-24.1.21, 24.2.0-24.2.20, or 26.1.0-26.1.4.
- Restrict network access to Oracle APEX endpoints using firewalls or access control lists to limit exposure to untrusted networks.
- Monitor HTTPS traffic logs for unusual activity or unauthorized access attempts targeting the APEX service.
- Contact Oracle support or review official advisories for updates regarding a fix for CVE-2026-101521.
What to do and how to stay safe: Oracle APEX
- Vulnerability severity scores ignore your specific architecture and context.
- Exploitability depends on network exposure and user behavior, not just code flaws.
- Prioritization requires continuous asset inventory and threat intelligence alignment.
Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
Which Oracle APEX versions are vulnerable to CVE-2026-101521?
Versions 24.1.0 through 24.1.21, 24.2.0 through 24.2.20, and 26.1.0 through 26.1.4 are affected.
What is the CVSS score for this vulnerability?
The CVSS 3.1 Base Score is 9.8, which is rated as critical.
Can an attacker exploit this flaw without logging in?
Yes, the vulnerability allows unauthenticated attackers to compromise the system via HTTPS.
