CVE-2026-20311: Buffer Over-read in Cisco Cisco IOS XE Software
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 vulnerability is due to insufficient error handling in the web-based management interface. An attacker could exploit this vulnerability by authenticating with a malformed certificate. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
AI Analysis
Technical Summary
This vulnerability affects the web-based management interface of Cisco IOS XE Software. An attacker who can authenticate with low privileges can exploit insufficient error handling by submitting a malformed certificate. Successful exploitation causes the affected device to reload, resulting in a denial of service condition. The CVSS 3.1 base score is 6.3, reflecting network attack vector, high attack complexity, low privileges required, no user interaction, and impact limited to availability. The vulnerability is present in numerous specific versions of Cisco IOS XE Software as enumerated.
Potential Impact
The impact is a denial of service condition caused by device reloads, which disrupts availability of the affected Cisco IOS XE device. There is no confidentiality or integrity impact reported. The attacker must be authenticated with low privileges, limiting the attack surface to authorized users.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Until a patch is available, restrict access to the web-based management interface to trusted users and monitor for suspicious authentication attempts with malformed certificates.
CVE-2026-20311: Buffer Over-read in Cisco Cisco IOS XE Software
Description
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 vulnerability is due to insufficient error handling in the web-based management interface. An attacker could exploit this vulnerability by authenticating with a malformed certificate. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
CVSS v3.1
Score 6.3medium
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability affects the web-based management interface of Cisco IOS XE Software. An attacker who can authenticate with low privileges can exploit insufficient error handling by submitting a malformed certificate. Successful exploitation causes the affected device to reload, resulting in a denial of service condition. The CVSS 3.1 base score is 6.3, reflecting network attack vector, high attack complexity, low privileges required, no user interaction, and impact limited to availability. The vulnerability is present in numerous specific versions of Cisco IOS XE Software as enumerated.
Potential Impact
The impact is a denial of service condition caused by device reloads, which disrupts availability of the affected Cisco IOS XE device. There is no confidentiality or integrity impact reported. The attacker must be authenticated with low privileges, limiting the attack surface to authorized users.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Until a patch is available, restrict access to the web-based management interface to trusted users and monitor for suspicious authentication attempts with malformed certificates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- cisco
- Date Reserved
- 2025-10-08T11:59:15.409Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a736b62bf8831d5392da51e
Added to database: 08/05/2026, 16:57:06 UTC
Last enriched: 08/05/2026, 17:16:53 UTC
Last updated: 08/05/2026, 21:38:04 UTC
Views: 6
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