Is CVE-2026-123856 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123856 being exploited in the wild.

How severe is CVE-2026-123856?

Medium severity, with a CVSS score of 6.5, published 6 November 2026.

Which products and versions are affected?

Jetbrains Toolbox App before 3.6.1.

Is there a fix for CVE-2026-123856?

Yes: fixed in Toolbox App 3.6.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-123856 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-123856?

Check whether you run Jetbrains Toolbox App at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-123856: JetBrains Toolbox App nTLM hash disclosure via SVG icons

CVE-2026-123856 · Severity: medium · CVSS 6.5 · Published 2026-11-06

JetBrains Toolbox App, which manages development tools and remote connections, could leak NTLM authentication hashes when displaying SVG icons from a Remote Development server. An attacker controlling a malicious Remote Development server could capture credentials, potentially gaining unauthorized access to developer workstations and corporate networks.

Technologies: Jetbrains Toolbox App. Vendors: Jetbrains.

Quick answers

Is CVE-2026-123856 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123856 being exploited in the wild.
How severe is CVE-2026-123856?: Medium severity, with a CVSS score of 6.5, published 6 November 2026.
Which products and versions are affected?: Jetbrains Toolbox App before 3.6.1.
Is there a fix for CVE-2026-123856?: Yes: fixed in Toolbox App 3.6.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-123856 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-123856?: Check whether you run Jetbrains Toolbox App at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: Toolbox App 3.6.1

Technical details

A cross-origin SVG icon loading vulnerability in Toolbox App versions before 3.6.1 allows unauthenticated NTLM credential leakage. When the application renders SVG tool icons from a Remote Development server, the SVG processing triggers automatic NTLM authentication with embedded credentials, allowing the remote server to capture hashes. This requires the attacker to control or compromise the Remote Development server.

Affected products

JetBrains Toolbox App before 3.6.1

Timeline

2026-11-06: disclosed

References

https://www.jetbrains.com/privacy-security/issues-fixed/

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