CVE-2026-35300 Deserialization in WebLogic Server

Critical 9.8 Published 16 Jun 2026 Updated 18 Jun 2026

Unauthenticated attackers can achieve full server takeover via network access due to a deserialization flaw in Oracle WebLogic Server.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-35300?

CVE-2026-35300 is a critical unsafe deserialization vulnerability in Oracle Weblogic Server, published on 16 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Vulnerability in the WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are 12.2.1.4.0, 14.1.1.0.0, 14.1.2.0.0 and 15.1.1.0.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via TCP to compromise WebLogic Server. Successful attacks of this vulnerability can result in takeover of WebLogic Server. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Weakness: CWE-502

Which versions are affected by CVE-2026-35300?

It affects 1 product.

Products include Oracle Weblogic Server.

How do I fix CVE-2026-35300?

No fix has been published for CVE-2026-35300 yet. Limit exposure of the affected software until one is available.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-35300 being exploited?

There is no known exploitation of CVE-2026-35300 in the wild and no public exploit code.

All Oracle Weblogic Server vulnerabilities

Sources

Also known as GHSA-3437-gj43-rx9g.