U.S. CISA adds maximum-severity Oracle flaw to its Known Exploited Vulnerabilities catalog

U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Oracle flaw to its Known Exploited Vulnerabilities catalog.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added an Oracle HTTP Server and Oracle Weblogic Server Proxy Plug-in flaw, tracked as CVE-2026-21962 (CVSS score of 10,0), to its Known Exploited Vulnerabilities (KEV) catalog.

CVE-2026-21962 is a critical, unauthenticated vulnerability affecting the Oracle HTTP Server and Oracle WebLogic Server Proxy Plug-in for Apache HTTP Server and IIS.

An attacker does not need an account or valid credentials. With network access, they can exploit the flaw remotely through HTTP and potentially compromise the affected server. Successful exploitation could allow the attacker to access, modify or delete critical data, potentially gaining broad access to information available through the affected components.

“Oracle HTTP Server and Oracle WebLogic Server Proxy Plug-in contain an improper access control vulnerability that can result in unauthorized creation, deletion, or modification access to critical data as well as unauthorized access to critical data or complete access to all Oracle HTTP Server and Oracle WebLogic Server Proxy Plug-in accessible data,” CISA reports.

The vulnerability also has a scope-change impact, meaning an attacker who exploits it could potentially affect other systems or applications connected to the vulnerable Oracle components.

The flaw affects versions: 12.2.1.4.0, 14.1.1.0.0 and 14.1.2.0.0.

In practical terms, this is dangerous because an internet-accessible Oracle WebLogic proxy component could provide an attacker with a path into critical backend systems without requiring authentication.

In March 2026, CloudSEK researchers detected attacks targeting several known flaws in Oracle WebLogic against its honeypot network. Attackers also targeted CVE-2026-21962 along with older WebLogic RCE vulnerabilities, including CVE-2020-14882/14883, CVE-2020-2551 and CVE-2017-10271.

“This report analyzes attack data collected from a high-interaction honeypot simulating a vulnerable Oracle WebLogic Server (v14.1.1.0.0) over a 12-day period (Jan 22 – Feb 3, 2026). The primary focus is the immediate and widespread exploitation of the newly disclosed, critical unauthenticated Remote Code Execution (RCE) vulnerability, CVE-2026-21962 (CVSS: 10.0).” ” reads the report published CloudSEK.

“In addition to CVE-2026-21962, the honeypot captured attacks targeting other persistent, critical WebLogic RCE flaws, including CVE-2020-14882/14883 (Console RCE), CVE-2020-2551 (IIOP RCE), and CVE-2017-10271 (WLS-WSAT RCE). This confirms that threat actors continue to rely on a small set of highly-effective, simple-to-exploit vulnerabilities to compromise WebLogic environments.”

According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog.

Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure.

CISA orders federal agencies to fix the flaw by August 27, 2026.

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Pierluigi Paganini

(SecurityAffairs – hacking, CISA)