EKFiddle

EKFiddle v.1.2.6 An extension/rules for the Fiddler Classic web debugger to analyze malicious web traffic. Fiddler Classic Installation Download and install Fiddler from here: https://www.telerik.com/fiddler Download and run EKFiddleExtension.exe Alternatively, download EKFiddle.dll and put it in...

CVE-2026-77804

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use TOCTOU race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary...

CVE-2026-77803

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, front-end request desynchronization is possible in the proxy request forwarding component. A request that contains both a Content-Length and a Transfer-Encoding header is forwarded with both headers present,...

CVE-2026-77802

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, HTTP request smuggling is possible in the proxy request forwarding component. Requests containing multiple Content-Length headers with conflicting values are forwarded verbatim to the origin server, while...

CVE-2026-77805

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode...

EUVD-2026-92428

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode...

CVE-2026-77805

Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021 , is vulnerable to a weak executable signature verification flaw. The application fails to verify that external helper tools are the specific executables shipped with the product; instead, it only checks if the fi...

CVE-2026-77805 Weak Executable Signature Verification Vulnerability in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, the integrity check applied to the external helper tools launched by the application is insufficient. Before executing a helper tool, the application only verifies that the file carries a valid Authenticode...

CVE-2026-77804 Time-of-check Time-of-use (TOCTOU) Race Condition in Root Certificate Installation in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use TOCTOU race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary...

EUVD-2026-92427

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use TOCTOU race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary...

CVE-2026-77804

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021 , a time-of-check time-of-use (TOCTOU) race condition exists during the installation of the HTTPS interception root certificate. The software writes a certificate to a user-writable temporary file before launch...

CVE-2026-77804 Time-of-check Time-of-use (TOCTOU) Race Condition in Root Certificate Installation in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use TOCTOU race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary...

CVE-2026-77803 Front-end Desynchronization Vulnerability in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, front-end request desynchronization is possible in the proxy request forwarding component. A request that contains both a Content-Length and a Transfer-Encoding header is forwarded with both headers present,...

CVE-2026-77803

Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021 , contains a front-end request desynchronization vulnerability in the proxy request forwarding component. The root cause is that the software forwards requests containing both Content-Length and Transfer-Encoding ...

EUVD-2026-92426

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, front-end request desynchronization is possible in the proxy request forwarding component. A request that contains both a Content-Length and a Transfer-Encoding header is forwarded with both headers present,...

CVE-2026-77802

Progress Telerik Fiddler Classic for Windows versions prior to v6.0.20262.10021 are vulnerable to HTTP request smuggling in the proxy request forwarding component. The issue arises because the software forwards requests with multiple conflicting Content-Length headers verbatim, while only using t...

CVE-2026-77802 HTTP Request Smuggling Vulnerability in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, HTTP request smuggling is possible in the proxy request forwarding component. Requests containing multiple Content-Length headers with conflicting values are forwarded verbatim to the origin server, while...

CVE-2026-77802 HTTP Request Smuggling Vulnerability in Progress® Telerik® Fiddler® Classic

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, HTTP request smuggling is possible in the proxy request forwarding component. Requests containing multiple Content-Length headers with conflicting values are forwarded verbatim to the origin server, while...

EUVD-2026-92425

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, HTTP request smuggling is possible in the proxy request forwarding component. Requests containing multiple Content-Length headers with conflicting values are forwarded verbatim to the origin server, while...

PT-2026-105989

In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use TOCTOU race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary...