CVE-2026-53914 JetBrains Kotlin: Unsafe Deserialization in Kotlin Build Cache Enables Code Execution
Unsafe deserialization in Kotlin build cache metadata allows attackers to execute arbitrary code, requiring developers to upgrade the compiler.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53914?
CVE-2026-53914 is a medium-severity unsafe deserialization vulnerability in JetBrains Kotlin, published on 26 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata
Weakness: CWE-502
Which versions are affected by CVE-2026-53914?
2 open source packages ship an affected version, including org.jetbrains.kotlin:kotlin-gradle-plugin. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
org.jetbrains.kotlin:kotlin-gradle-plugin Maven | All versions | 2.4.20-Beta1 |
org.jetbrains.kotlin:kotlin-gradle-plugin Maven | All versions | 2.4.20-Beta1 |
Products include Jetbrains Kotlin.
How do I fix CVE-2026-53914?
Upgrade org.jetbrains.kotlin:kotlin-gradle-plugin to 2.4.20-Beta1 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-53914 being exploited?
There is no known exploitation of CVE-2026-53914 in the wild and no public exploit code.
Other vulnerabilities in JetBrains Kotlin
Sources
Also known as CLSA-2026-1793139590, GHSA-r937-wjx7-w2jp.