---
title: "CVE-2026-77805: In Progress Telerik Fiddler Classic - Privilege Escalation"
description: "In Progress Telerik Fiddler Classic for Windows < 6.0.20262.10021 contains a privilege escalation caused by insufficient integrity checks on external helper tools, letting local low-privilege attackers execute unintended code with elevated privileges, exploit requires user to launch the tool and approve elevation prompt."
url: https://panop.io/threat-heartbeat/CVE-2026-77805/
---

# CVE-2026-77805 In Progress Telerik Fiddler Classic - Privilege Escalation

In Progress Telerik Fiddler Classic for Windows < 6.0.20262.10021 contains a privilege escalation caused by insufficient integrity checks on external helper tools, letting local low-privilege attackers execute unintended code with elevated privileges, exploit requires user to launch the tool and approve elevation prompt.

CVSS base score 7.9 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.06% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-77805)

## Details

Type

Privilege Escalation

Impact

Privilege Escalation, Remote Code Execution

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Published

5 October 2026

Updated

15 October 2026

Weakness

[CWE-347](https://cwe.mitre.org/data/definitions/347.html)

## Vendor fix

Update to version 6.0.20262.10021 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-77805](https://nvd.nist.gov/vuln/detail/CVE-2026-77805)
- [https://docs.telerik.com/fiddler/knowledge-base/kb-security-weak-executable-signature-verification-cve-2026-77805](https://docs.telerik.com/fiddler/knowledge-base/kb-security-weak-executable-signature-verification-cve-2026-77805)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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