CVE-2026-53914

Code execution via build-cache metadata deserialization

Published Jun 26, 2026 · Updated Jun 26, 2026

Unsafe deserialization in JetBrains Kotlin before 2.4.20 allows local users to execute code through crafted build-cache metadata. Kotlin build tooling deserializes build-cache metadata without sufficiently restricting the object data it accepts. Exploitation requires high local privileges and high attack complexity; successful execution runs code in the context of the build process.

CVSS severity6.7
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in JetBrains Kotlin before 2.4.20 allows local users to execute code through crafted build-cache metadata. Kotlin build tooling deserializes build-cache metadata without sufficiently restricting the object data it accepts. Exploitation requires high local privileges and high attack complexity; successful execution runs code in the context of the build process.

The record

CVE
CVE-2026-53914
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
JetBrains
Product
Kotlin
Classifications
CWE-502, T1203
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.4.20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

JetBrains · Kotlinversion=0 <2.4.20

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.7JetBrains s.r.o.CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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