Cisco Secure Web Appliance up to 15.2.5-013 Authentication Service authentication bypass

Summaryinfo

A vulnerability has been found in Cisco Secure Web Appliance and classified as problematic. This vulnerability affects unknown code of the component Authentication Service. This manipulation causes authentication bypass. This vulnerability is registered as CVE-2026-20152. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Cisco Secure Web Appliance and classified as problematic. Affected by this vulnerability is an unknown part of the component Authentication Service. The manipulation with an unknown input leads to a authentication bypass vulnerability. The CWE definition for the vulnerability is CWE-305. The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. As an impact it is known to affect integrity. The summary by CVE is:

A vulnerability in the authentication service feature of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to bypass authentication policy requirements. This vulnerability is due to improper validation of user-supplied authentication input in HTTP requests. An attacker could exploit this vulnerability by sending HTTP requests that contain specific authentication requests to an affected device. A successful exploit could allow the attacker to bypass policy enforcement on the device. There is no direct impact to the Cisco Secure Web Appliance. However, as a result of exploiting this vulnerability, an attacker could send HTTP requests that should be restricted through the device.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-20152 since 10/08/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/16/2026).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-22964). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Cisco

Name

• Secure Web Appliance

Version

• 11.8.0-414
• 11.8.0-429
• 11.8.0-453
• 11.8.1-023
• 11.8.3-018
• 11.8.3-021
• 11.8.4-004
• 12.0.1-268
• 12.0.1-334
• 12.0.2-004
• 12.0.2-012
• 12.0.3-005
• 12.0.3-007
• 12.0.4-002
• 12.0.5-011
• 12.5.1-011
• 12.5.1-043
• 12.5.2-007
• 12.5.2-011
• 12.5.3-002
• 12.5.4-005
• 12.5.4-011
• 12.5.5-004
• 12.5.5-005
• 12.5.5-008
• 12.5.6-008
• 14.0.1-014
• 14.0.1-040
• 14.0.1-053
• 14.0.1-503
• 14.0.2-012
• 14.0.3-014
• 14.0.4-005
• 14.0.5-007
• 14.1.0-032
• 14.1.0-041
• 14.1.0-047
• 14.5.0-498
• 14.5.0-537
• 14.5.0-673
• 14.5.1-008
• 14.5.1-016
• 14.5.1-510
• 14.5.1-607
• 14.5.2-011
• 14.5.3-033
• 14.6.0-108
• 15.0.0-322
• 15.0.0-355
• 15.0.1-004
• 15.1.0-287
• 15.2.0-116
• 15.2.0-164
• 15.2.1-011
• 15.2.2-009
• 15.2.3-007
• 15.2.4-022
• 15.2.5-011
• 15.2.5-013

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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