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Vulnerability record · CVE-2025-20363 · published 25 September 2025

CVE-2025-20363: Cisco ios xr heap-based buffer overflow vulnerability

Cisco · Ios Xr

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.

9.0 CVSS 3.1 Critical EPSS 6.9% · top 6.1% CWE-122 · Heap-based buffer overflow
9.0CVSS 3.1 base score
6.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
5Affected product versions listed by NVD
1References
11 Aug 2026Last modified by NVD

Description

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

5 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-http-code-exec-WmfP3h3O Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-20363), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.