CVE-2026-57926Network attack vector

Integrity loss via websandbox bridge prototype pollution

Published Jun 26, 2026 · Updated Jun 26, 2026

Prototype pollution in the websandbox bridge in JetBrains YouTrack before 2026.2.16593 allows remote authenticated users to cause integrity loss. JetBrains identifies the bridge but has not disclosed the affected function, input path, or unsafe operation that modifies object prototype attributes. Exploitation requires a network-reachable authenticated account, high-complexity conditions, and user interaction; the published vendor impact is limited to integrity.

CVSS severity2.6
Low
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in the websandbox bridge in JetBrains YouTrack before 2026.2.16593 allows remote authenticated users to cause integrity loss. JetBrains identifies the bridge but has not disclosed the affected function, input path, or unsafe operation that modifies object prototype attributes. Exploitation requires a network-reachable authenticated account, high-complexity conditions, and user interaction; the published vendor impact is limited to integrity.

The record

CVE
CVE-2026-57926
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
JetBrains
Product
YouTrack
Classifications
CWE-1321
Attack vector
network
Privileges
authenticated

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 <2026.2.16593

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

JetBrains · YouTrackversion=0 <2026.2.16593

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
2.6JetBrains s.r.o.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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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