Is CVE-2026-105798 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-105798 being exploited in the wild.

How severe is CVE-2026-105798?

High severity, with a CVSS score of 8.7, published 6 October 2026.

Which products and versions are affected?

Microsoft SimpleChat <= 0.250.001.

How is CVE-2026-105798 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-105798?

Check whether you run Microsoft SimpleChat 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-2026-105798: SimpleChat stored XSS in group document filename

Q: Is there a fix for CVE-2026-105798?

Yes: fixed in 0.261.029. Until then: Disable group workspaces by setting enable_group_workspaces=False in functions_settings.py until upgrading to the patched version. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-105798 attacked?

It is attacked over the network, in a web application.

Q: Am I affected by CVE-2026-105798?

Check whether you run Microsoft SimpleChat 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-2026-105798 · Severity: high · CVSS 8.7 · Published 2026-10-06

SimpleChat is an AI conversation application that lets users collaborate in group workspaces and share documents. An authenticated group member with DocumentManager, Admin, or Owner role can upload a file with a malicious filename containing JavaScript code. When another group member clicks the Share button on this document, the attacker's script executes in the victim's browser session, potentially exposing sensitive data or allowing unauthorized actions.

Technologies: Microsoft SimpleChat. Vendors: Microsoft.

Quick answers

Is CVE-2026-105798 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-105798 being exploited in the wild.
How severe is CVE-2026-105798?: High severity, with a CVSS score of 8.7, published 6 October 2026.
Which products and versions are affected?: Microsoft SimpleChat <= 0.250.001.
Is there a fix for CVE-2026-105798?: Yes: fixed in 0.261.029. Until then: Disable group workspaces by setting enable_group_workspaces=False in functions_settings.py until upgrading to the patched version. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-105798 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-105798?: Check whether you run Microsoft SimpleChat 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: 0.261.029

Disable group workspaces by setting enable_group_workspaces=False in functions_settings.py until upgrading to the patched version.

Technical details

This is a stored cross-site scripting (XSS) vulnerability in the group document upload and rendering flow. The POST /api/group_documents/upload endpoint accepts client-supplied filenames without sanitization, stores them verbatim in the database, and later interpolates them into inline onclick event handlers in group_workspaces.html. Neither escapeGroupHtml() (which does not encode apostrophes) nor escapeHtml() (which encodes ' as &#39; but is decoded back to ' by the HTML parser before JavaScript evaluation) provides effective protection. Requires authentication and group membership; exploit triggers when a victim interacts with the malicious document.

Affected products

Microsoft SimpleChat <= 0.250.001

Timeline

2026-09-19: disclosed
2026-09-18: patched: Fix commit authored 2026-09-18, published as version 0.261.029
2026-10-06: advisory

References

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