CVE-2025-20240
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk19th percentile - higher than 19% of all known CVEs
Summary
A vulnerability in the Web Authentication feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting attack (XSS) on an affected device. This is due to improper sanitization of user-supplied input.
Risk Assessment
An attacker could persuade a user to click a malicious link and steal their session cookies, potentially leading to session hijacking on the device.
Recommendation
Install Cisco IOS XE Software updates containing the fix and inform users about the risks of clicking unknown links.
Other vulnerabilities in Cisco IOS XE Software
See all- CVE-2026-20104Medium
A vulnerability in the bootloader of Cisco IOS XE Software for Cisco Catalyst 9200, ESS9300, IE9310, IE9320, IE3500, and IE3505 switches could allow an authenticated local attacker with level-15 privileges or an unauthenticated attacker with physical access to execute arbitrary code at boot time and break the chain of trust. This is due to insufficient validation of software at boot time, enabling manipulation of loaded binaries to bypass integrity checks.
- CVE-2026-20272Critical
As part of an internal security review in Cisco IOS XE Software, multiple vulnerabilities related to improper neutralization of special elements (CWE-74) were discovered. Hardened software releases addressing these issues have been issued.
- CVE-2026-20267Critical
Vulnerability in Cisco IOS XE Software, discovered during an internal security review, involves improper access control issues classified under CWE-284. Hardened releases have been issued as a result.
- CVE-2023-20273HighActively exploited
A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to inject commands with the privileges of root. This is due to insufficient input validation.
- CVE-2023-20198CriticalActively exploited
Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. The attacker exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user, then exploited another component (CVE-2023-20273) to elevate privilege to root and write an implant. CVE-2023-20198 has a CVSS score of 10.0, CVE-2023-20273 has a CVSS score of 7.2.
- CVE-2017-12319MediumActively exploited
A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. This vulnerability affects all releases of Cisco IOS XE Software prior to software release 16.3 that support BGP EVPN configurations.
- CVE-2017-12229Critical
A vulnerability in the web-based user interface (web UI) of Cisco IOS XE 3.1 through 16.5 allows an unauthenticated remote attacker to bypass authentication to the REST API. The issue is due to insufficient input validation for the REST API.
- CVE-2026-20311Medium
A vulnerability in the web-based management interface of Cisco IOS XE Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on an affected device. This is due to insufficient error handling in the web-based management interface. An attacker could exploit this by authenticating with a malformed certificate, potentially causing the device to reload.
- CVE-2026-20308Medium
A vulnerability in the web-based management interface of Cisco IOS XE Software allows an authenticated remote attacker with low privileges to perform a DoS attack. The issue is due to insufficient input validation, and exploitation can make the interface unresponsive.
- CVE-2026-20273High
A vulnerability in Cisco IOS XE Software related to improper input validation (CWE-20), discovered during an internal security review. It is addressed in a software hardening release.
Original NVD description (English source)
A vulnerability in the Web Authentication feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting attack (XSS) on an affected device. This vulnerability is due to improper sanitization of user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute a reflected XSS attack and steal user cookies from the affected device.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS