Review reviewCritical

CVE-2026-53914

JetBrains Kotlin, kotlin

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

CVSS
9.8
EPSS
0.20%
9.59% percentile
CISA KEV
Not listed
Published
2026.06.26
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.20%
Technical severityCVSS 9.8

Vulnerability overview

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

Affected product and versions

Product
JetBrains Kotlin, kotlin
Affected versions
< 2.4.20
Fixed versions
2.4.20

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that JetBrains Kotlin, kotlin and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-502
CVE-2026-53914 — JetBrains Kotlin, kotlin | SECUFOCUS NOW