Cisco IOS XE Software Unified Threat Defense Snort Intrusion Prevention System Engine Multiple Vulnerabilities (cisco-sa-snort3-dcerpc-vulns-J9HNF4tH)

medium Nessus Plugin ID 290255

Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco IOS-XE Software is affected by the following vulnerabilities:

- A vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer use-after-free read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to unexpectedly restart the Snort 3 Detection Engine, which could cause a denial of service (DoS). (CVE-2026-20026)

- A vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer out-of-bounds read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to obtain sensitive information in the Snort 3 data stream. (CVE-2026-20027)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCwq75339, CSCwq75359, CSCwr21376, CSCwr21389

Plugin Details

Severity: Medium

ID: 290255

File Name: cisco-sa-snort3-dcerpc-vulns-J9HNF4tH-iosxe.nasl

Version: 1.1

Type: combined

Family: CISCO

Published: 1/16/2026

Updated: 1/16/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.9

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2026-20026

CVSS v3

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 5.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:ios_xe

Required KB Items: Host/Cisco/IOS-XE/Version, Host/Cisco/IOS-XE/Model

Exploit Ease: No known exploits are available

Patch Publication Date: 1/7/2026

Vulnerability Publication Date: 1/7/2026

Reference Information

CVE: CVE-2026-20026, CVE-2026-20027

CWE: 200, 415

CISCO-SA: cisco-sa-snort3-dcerpc-vulns-J9HNF4tH

IAVA: 2026-A-0029

CISCO-BUG-ID: CSCwq75339, CSCwq75359, CSCwr21376, CSCwr21389

Detections

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