High · CVSS 8.9CVE-2026-106155

Stored Cross-site Scripting (XSS) in Telerik Report Server Web Report ViewersCVE-2026-106155

Answer in brief

CVE-2026-106155 records a High severity (CVSS 8.9) vulnerability in Stored Cross-site Scripting (XSS) in Telerik Report Server Web Report Viewers. The current sources do not mark it as known exploited. The current feed maps Progress Software/Telerik Report Server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 9, 2026Updated Oct 9, 2026Source checked Oct 9, 2026First seen by HOL Oct 9, 2026Material review Oct 9, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Progress Software/Telerik Report Server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Progress Software/Telerik Report Servergeneric	>=0 <12.2.26.1007	12.2.26.1007

Recommended response

Check inventory. Check lockfiles and deployed manifests for Progress Software/Telerik Report Server.
Review the reported fix. Update Progress Software/Telerik Report Server to 12.2.26.1007 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 9, 2026

Sources and claim methodology

Source referencetelerik.com

Upstream source description

In Progress® Telerik® Report Server prior to version 12.2.26.1007, a stored cross-site scripting vulnerability in the shared reporting engine allows an authenticated report author to embed javascript: or vbscript: URLs in report navigation actions or HTML text box links. When another user views the malicious report and the embedded navigation is triggered, attacker-controlled script can execute in the web report viewer's origin. In a multi-user Report Server deployment, this can enable privilege escalation by performing actions in a higher-privilege user's authenticated session, including an administrator's session.

Quoted source text, attributed separately from HOL analysis.