CVE-2026-53914

JetBrains Kotlin: Unsafe Deserialization in Kotlin Build Cache Enables Code Execution

6.7 MediumFix available

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: High
Privileges needed: High
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: Low
Availability: Low

Exploit likelihood

0.35%Up 0.2 points since Jun 27, 2026

What each source reports

CVE List Score used 6.7

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: CVE-2026-53914
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-502, CWE-502
Updated: 2026-11-02

EUVDEUVD-2026-39659 6.7

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: EUVD-2026-39659
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Updated: 2026-11-02

GitHub AdvisoriesGHSA-r937-wjx7-w2jp 6.7

JetBrains Kotlin: Unsafe Deserialization in Kotlin Build Cache Enables Code Execution

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: GHSA-r937-wjx7-w2jp
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-502
Updated: 2026-11-02

NVD 6.7

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: CVE-2026-53914
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-502
Updated: 2026-11-02

OSV 6.7

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: CVE-2026-53914
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-502
Updated: 2026-11-02

OSVGHSA-r937-wjx7-w2jp 6.7

JetBrains Kotlin: Unsafe Deserialization in Kotlin Build Cache Enables Code Execution

In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

Record: GHSA-r937-wjx7-w2jp
CVSS 3.1: 6.7 MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
Weakness: CWE-502
Updated: 2026-11-02

OSVCLSA-2026-1793139590 No score

TuxCare security update for org.jetbrains.kotlin:kotlin-gradle-plugin (1 CVE)

TuxCare rebuilt org.jetbrains.kotlin:kotlin-gradle-plugin to address 1 CVE. Fixed in 1.9.24-tuxcare.1.

Record: CLSA-2026-1793139590
Updated: 2026-11-02

OSVCLSA-2026-1794245205 No score

TuxCare security update for org.jetbrains.kotlin:kotlin-gradle-plugin (1 CVE)

TuxCare rebuilt org.jetbrains.kotlin:kotlin-gradle-plugin to address 1 CVE. Fixed in 1.9.25-tuxcare.1.

Record: CLSA-2026-1794245205
Updated: 2026-11-10

Affected products

jetbrains kotlin

Affected packages

Affected packages
Package	Affected	Fixed
`org.jetbrains.kotlin:kotlin-gradle-plugin` Maven	before 2.4.20-Beta1	2.4.20-Beta1
`org.jetbrains.kotlin:kotlin-gradle-plugin` TuxCare:Maven	1.9.24 up to 1.9.24-tuxcare.1	1.9.24-tuxcare.1
`org.jetbrains.kotlin:kotlin-gradle-plugin` TuxCare:Maven	1.9.25 up to 1.9.25-tuxcare.1	1.9.25-tuxcare.1
`org.jetbrains.kotlin:kotlin-gradle-plugin` Maven	before 2.4.20-Beta1, plus listed versions 0.0.1-test-deploy0.0.2-test-deploy0.1.1.2-5-test-20.1.1.2-5-test-40.1.1.2-5-test-5 Show 45 moreShow less 0.10.13160.10.1950.10.40.10.7090.10.7700.11.910.11.91.10.11.91.20.11.91.40.12.12180.12.12300.12.2000.12.2130.12.4120.12.6130.13.15130.13.15140.13.15160.14.4490.14.4510.5.11310.5.9980.6.10700.6.13150.6.14110.6.15070.6.15900.6.16030.6.16170.6.16580.6.16700.6.16730.6.1790.6.19100.6.220.6.24510.6.25170.6.310.6.3170.6.3500.6.5940.6.6020.6.690.6.7860.6.800	2.4.20-Beta1

History

History
Recorded	Changed	Sources
Nov 10, 2026	affected, aliases, facts	OSV
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-53914 is a medium vulnerability (CVSS 6.7) in Jetbrains Kotlin, published June 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 28th percentile. Fixed in org.jetbrains.kotlin:kotlin-gradle-plugin 2.4.20-Beta1.

References

This page doesn't list everything

Left out here: 247 versions. The JSON record has them.