CVE-2026-104656Progress Software Progress® Telerik® Fiddler® Everywhere cross-site scripting
CVE-2026-104656 is a cross-site scripting in Progress Software Progress® Telerik® Fiddler® Everywhere, rated high (7.3 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Awaiting Analysis
What it is
Input is written into a web page without escaping, so an attacker's script runs in the browser of anyone who views it.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, without an account, but someone has to act first, such as opening a file or following a link.
What an attacker gains
A successful attack can read the data it protects and change data or behaviour. In practice, this kind of flaw lets an attacker act inside a signed-in user's browser session.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Progress Software Progress® Telerik® Fiddler® Everywhere to 8.3.0 or later.
- Limit who can run code or sign in on the hosts that run it.
- Warn the people who use it, and filter files and links on the way in.
Description from NVD
Improper neutralization of input in the sessions grid in Progress Telerik Fiddler Everywhere 8.3.0 and earlier allows an attacker to execute backend IPC commands by convincing a user to open a specially crafted SAZ file.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Web front ends and single-page apps. The flaw sits between a user's browser and the web application.
- Admin consoles served to a browser. The flaw sits between a user's browser and the web application.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- People who open files and links. Mail, chat and browsers are the delivery path.
- Between a user's browser and the web application. An attacker who crosses it can act inside a signed-in user's browser session.
Questions to answer about your own systems
- Where does Progress Software Progress® Telerik® Fiddler® Everywhere run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.