VDB-353176 · CVE-2026-20086 · EUVD-2026-15433

Cisco IOS XE up to 17.18.1 CAPWAP missing values

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.9	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in Cisco IOS XE up to 17.18.1. Affected is an unknown function of the component CAPWAP. Executing a manipulation can lead to improper handling of missing values. This vulnerability is handled as CVE-2026-20086. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Cisco IOS XE up to 17.18.1. It has been declared as critical. This vulnerability affects an unknown code block of the component CAPWAP. The manipulation with an unknown input leads to a improper handling of missing values vulnerability. The CWE definition for the vulnerability is CWE-230. The product does not handle or incorrectly handles when a parameter, field, or argument name is specified, but the associated value is missing, i.e. it is empty, blank, or null. As an impact it is known to affect availability. CVE summarizes:

A vulnerability in the processing of Control and Provisioning of Wireless Access Points (CAPWAP) packets of Cisco IOS XE Wireless Controller Software for the Catalyst CW9800 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of a malformed CAPWAP packet. An attacker could exploit this vulnerability by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload unexpectedly, resulting in a DoS condition.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability was named CVE-2026-20086 since 10/08/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/31/2026).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-15433). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Router Operating System

Vendor

Cisco

Name

IOS XE

Version

License

commercial

Website

Vendor: https://www.cisco.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (cisco): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper handling of missing values
CWE: CWE-230 / CWE-229 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/08/2025 CVE reserved
03/25/2026 +168 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
03/31/2026 +5 days VulDB entry last update

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-wlc-dos-hnX5KGOm
Status: Confirmed

CVE: CVE-2026-20086 (🔒)
GCVE (CVE): GCVE-0-2026-20086
GCVE (VulDB): GCVE-100-353176
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20150108

Entryinfo

Created: 03/25/2026 17:23
Updated: 03/31/2026 01:10
Changes: 03/25/2026 17:23 (64), 03/25/2026 18:28 (1), 03/31/2026 01:10 (1)
Complete: 🔍
Cache ID: 216:1FD:103

VulDB is the best source for vulnerability data and more expert information about this specific topic.