CVE-2026-20028

Cisco Terminal Services Agent Firewall Rules Bypass Vulnerability

State
Published
Severity
5.0 Medium
Published
Aug 5, 2026
Updated
Aug 5, 2026
Reserved
Oct 8, 2025

Read the record on cve.org

Description

A vulnerability in the network driver of Cisco Terminal Service (TS) Agent could allow an authenticated, remote attacker to bypass firewall rules that are associated with the account of the attacker.

This vulnerability is due to an incorrect mapping of network connections to user accounts. An attacker with at least user-level credentials could exploit this vulnerability by sending crafted network traffic to an affected device. A successful exploit could allow the attacker to inherit the firewall rules associated with a different user in the system.

Scores

CVSSScoreVectorSource
3.15.0 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:Ncisco

Weaknesses

  • CWE-266 Incorrect Privilege Assignment

Affected Products

ProductVersions
Cisco Terminal Services AgentCisco
  • TSAgent-1.3Affected
  • TSAgent-1.4.2Affected
  • TSAgent-1.2Affected
  • TSAgent-1.4Affected
  • TSAgent-1.0Affected
  • TSAgent-1.4.1Affected
  • TSAgent-1.1Affected

References

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