CVE-2026-86491Network attack vector

Stored XSS via project and organization icons

Published Sep 7, 2026 · Updated Sep 8, 2026

Stored XSS in JetBrains YouTrack before 2026.2.18634 allows remote authenticated users to run script via project or organization icons. JetBrains has not disclosed which accepted icon format or rendering path fails to neutralize executable content. High privileges are required to upload the icon, and another user must view it; injected script can read or alter data available to that browser session.

CVSS severity3.5
Low
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in JetBrains YouTrack before 2026.2.18634 allows remote authenticated users to run script via project or organization icons. JetBrains has not disclosed which accepted icon format or rendering path fails to neutralize executable content. High privileges are required to upload the icon, and another user must view it; injected script can read or alter data available to that browser session.

The record

CVE
CVE-2026-86491
Published
Sep 7, 2026
Updated
Sep 8, 2026
Vendor
JetBrains
Product
YouTrack
Classifications
CWE-79, CAPEC-592, T1203
Attack vector
network
Privileges
admin

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 privilegesadmin

What is affected?

JetBrains · YouTrackversion=0 <2026.2.18634

Published CVSS scores

3.5JetBrainsCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/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.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
T1203Exploitation for Client Execution

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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