CVE-2026-65906Network attack vector

Authenticated code execution via Kotlin DSL sandbox escape

Published Jul 23, 2026 · Updated Jul 23, 2026

Code injection in TeamCity On-Premises before 2025.11.6 and 2026.1 through 2026.1.1 allows remote authenticated users to execute code. JetBrains identifies a Kotlin DSL sandbox escape but has not published the affected evaluator or the sandbox check that mishandles DSL input. A low-privileged TeamCity account and network access are required; successful exploitation runs attacker-controlled code in the server context.

CVSS severity8.8
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in TeamCity On-Premises before 2025.11.6 and 2026.1 through 2026.1.1 allows remote authenticated users to execute code. JetBrains identifies a Kotlin DSL sandbox escape but has not published the affected evaluator or the sandbox check that mishandles DSL input. A low-privileged TeamCity account and network access are required; successful exploitation runs attacker-controlled code in the server context.

The record

CVE
CVE-2026-65906
Published
Jul 23, 2026
Updated
Jul 23, 2026
Vendor
JetBrains
Product
TeamCity On-Premises
Classifications
CWE-94, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 23, 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 <2026.1.2, 2025.11.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

JetBrains · TeamCity On-Premisesversion=0 <2026.1.2, 2025.11.6

Published CVSS scores

8.8JetBrainsCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
10.0NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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