CVE-2026-77805
Before executing a helper tool, the application only verifies that the file carries a valid Authenticode signature whose certificate subject name matches a broad allow list of publisher name fragments, rather than verifying that the file is the specific…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.07%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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 signature whose certificate subject name matches a broad allow list of publisher name fragments, rather than verifying that the file is the specific executable shipped with that version of the product. A local threat actor with low privileges who replaces one of these helper executables with any other validly signed binary from an allow-listed publisher can cause the substituted binary to be executed by the application, including with Administrator privileges for the tools that request elevation, resulting in privilege escalation and execution of unintended code. Successful exploitation requires the user to launch the affected external tool and to approve the elevation prompt without noticing that it refers to a different executable.
- CVSS 3.1
- 7.9 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- EPSS
- 0.07% probability · 0th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Source
- security@progress.com
EPSS moved from 0.1% on 6 October 2026 to 0.1% on 26 October 2026.
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.