CVE-2026-86490Network attack vector

Bundled app overwrite via improper import authorization

Published Sep 7, 2026 · Updated Sep 8, 2026

Improper authorization in JetBrains YouTrack before 2026.2.18634 allows remote authenticated users to overwrite bundled apps through app import. The app import endpoint accepts an imported app over an existing bundled app without correctly enforcing the permission boundary for that protected content. A low-privileged account and network access to the endpoint are required, and the demonstrated consequence is unauthorized modification of bundled application code or content.

CVSS severity6.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in JetBrains YouTrack before 2026.2.18634 allows remote authenticated users to overwrite bundled apps through app import. The app import endpoint accepts an imported app over an existing bundled app without correctly enforcing the permission boundary for that protected content. A low-privileged account and network access to the endpoint are required, and the demonstrated consequence is unauthorized modification of bundled application code or content.

The record

CVE
CVE-2026-86490
Published
Sep 7, 2026
Updated
Sep 8, 2026
Vendor
JetBrains
Product
YouTrack
Classifications
CWE-863, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 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 <2026.2.18634

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

JetBrains · YouTrackversion=0 <2026.2.18634

Published CVSS scores

6.5JetBrainsCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

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.

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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-863Incorrect Authorization
T1565.001Stored Data Manipulation

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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