CVE-2026-20124

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versions of SNMP — Versions 1, 2c, and 3. An attacker could exploit this vulnerability by sending a malformed SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly. The attacker must have the SNMPv1 or v2c read-only or read-write community string or valid SNMPv3 user credentials on the affected device.

CVSS v3 7.7 HIGH

7.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.1 / Impact : 4.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-snmp-dos-ZAqNm4MD

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-05 17:16

Updated : 2026-08-06 15:44

NVD link : CVE-2026-20124

Mitre link : CVE-2026-20124

CVE.ORG link : CVE-2026-20124

JSON object : View

Products Affected

No product.

CWE

CWE-772

Missing Release of Resource after Effective Lifetime

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{"status": "affected", "version": "17.2.2"}, {"status": "affected", "version": "16.9.8"}, {"status": "affected", "version": "16.9.7"}, {"status": "affected", "version": "17.1.3"}, {"status": "affected", "version": "17.3.1a"}, {"status": "affected", "version": "17.3.2a"}, {"status": "affected", "version": "16.12.5"}, {"status": "affected", "version": "17.3.1w"}, {"status": "affected", "version": "17.3.2"}, {"status": "affected", "version": "17.4.1"}, {"status": "affected", "version": "16.12.4a"}, {"status": "affected", "version": "17.4.1a"}, {"status": "affected", "version": "3.16.10bS"}, {"status": "affected", "version": "17.3.1x"}, {"status": "affected", "version": "17.3.3"}, {"status": "affected", "version": "16.6.9"}, {"status": "affected", "version": "17.2.3"}, {"status": "affected", "version": "17.5.1"}, {"status": "affected", "version": "16.12.1z1"}, {"status": "affected", "version": "16.12.5a"}, {"status": "affected", "version": "17.4.1b"}, {"status": "affected", "version": 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"affected", "version": "17.9.1y"}, {"status": "affected", "version": "16.9.8b"}, {"status": "affected", "version": "17.3.7"}, {"status": "affected", "version": "17.9.2a"}, {"status": "affected", "version": "17.9.3"}, {"status": "affected", "version": "16.12.9"}, {"status": "affected", "version": "17.11.1"}, {"status": "affected", "version": "17.10.1b"}, {"status": "affected", "version": "17.6.6"}, {"status": "affected", "version": "17.9.1x1"}, {"status": "affected", "version": "17.11.1a"}, {"status": "affected", "version": "17.9.3a"}, {"status": "affected", "version": "17.12.1"}, {"status": "affected", "version": "17.3.8"}, {"status": "affected", "version": "17.9.4"}, {"status": "affected", "version": "16.12.10"}, {"status": "affected", "version": "17.12.1w"}, {"status": "affected", "version": "17.9.1y1"}, {"status": "affected", "version": "17.12.1a"}, {"status": "affected", "version": "17.9.5"}, {"status": "affected", "version": "17.13.1"}, {"status": "affected", "version": "17.12.1x"}, {"status": "affected", "version": "17.12.2"}, {"status": "affected", "version": "17.14.1"}, {"status": "affected", "version": "17.9.4a"}, {"status": "affected", "version": "17.3.8a"}, {"status": "affected", "version": "17.6.6a"}, {"status": "affected", "version": "17.6.5a"}, {"status": "affected", "version": "17.6.7"}, {"status": "affected", "version": "16.12.10a"}, {"status": "affected", "version": "17.15.1"}, {"status": "affected", "version": "17.13.1a"}, {"status": "affected", "version": "17.12.2a"}, {"status": "affected", "version": "16.12.11"}, {"status": "affected", "version": "17.12.3"}, {"status": "affected", "version": "17.12.1y"}, {"status": "affected", "version": "17.12.1z"}, {"status": "affected", "version": "17.9.5a"}, {"status": "affected", "version": "17.14.1a"}, {"status": "affected", "version": "17.9.5b"}, {"status": "affected", "version": "17.6.8"}, {"status": "affected", "version": "16.12.12"}, {"status": "affected", "version": "17.12.4"}, {"status": "affected", "version": "17.9.6"}, {"status": "affected", "version": "17.17.1"}, {"status": "affected", "version": "17.16.1"}, {"status": "affected", "version": "17.15.1w"}, {"status": "affected", "version": "17.12.3a"}, {"status": "affected", "version": "17.9.5c"}, {"status": "affected", "version": "17.15.1a"}, {"status": "affected", "version": "17.12.1z1"}, {"status": "affected", "version": "17.15.2"}, {"status": "affected", "version": "17.15.1b"}, {"status": "affected", "version": "17.9.5d"}, {"status": "affected", "version": "17.15.1x"}, {"status": "affected", "version": "17.9.6a"}, {"status": "affected", "version": "17.12.1z2"}, {"status": "affected", "version": "17.6.8a"}, {"status": "affected", "version": "17.16.1a"}, {"status": "affected", "version": "16.12.13"}, {"status": "affected", "version": "17.15.3"}, {"status": "affected", "version": "17.9.7"}, {"status": "affected", "version": "17.12.5"}, {"status": "affected", "version": "17.15.1y"}, {"status": "affected", "version": "17.9.5e"}, {"status": "affected", "version": "17.12.4a"}, {"status": "affected", "version": "17.15.2a"}, {"status": "affected", "version": "17.15.2c"}, {"status": "affected", "version": "17.15.2b"}, {"status": "affected", "version": "17.12.1z3"}, {"status": "affected", "version": "17.9.5f"}, {"status": "affected", "version": "17.12.4b"}, {"status": "affected", "version": "17.12.5a"}, {"status": "affected", "version": "17.18.1"}, {"status": "affected", "version": "17.12.6"}, {"status": "affected", "version": "17.12.1z4"}, {"status": "affected", "version": "17.9.8"}, {"status": "affected", "version": "17.9.7a"}, {"status": "affected", "version": "17.15.3a"}, {"status": "affected", "version": "17.15.4"}, {"status": "affected", "version": "17.12.5b"}, {"status": "affected", "version": "17.15.3b"}, {"status": "affected", "version": "16.12.14"}, {"status": "affected", "version": "17.9.7b"}, {"status": "affected", "version": "17.12.5c"}, {"status": "affected", "version": "17.18.1a"}, {"status": "affected", "version": "17.15.4a"}, {"status": "affected", "version": "17.18.2"}, {"status": "affected", "version": "17.18.1w"}, {"status": "affected", "version": "17.15.4b"}, {"status": "affected", "version": "17.12.6a"}, {"status": "affected", "version": "17.15.4c"}, {"status": "affected", "version": "17.9.9"}, {"status": "affected", "version": "17.12.5d"}, {"status": "affected", "version": "16.12.15"}, {"status": "affected", "version": "17.15.4s1"}, {"status": "affected", "version": "17.12.1z5"}, {"status": "affected", "version": "17.18.1x"}, {"status": "affected", "version": "17.12.1z6"}, {"status": "affected", "version": "17.15.4d"}, {"status": "affected", "version": "17.12.6b"}, {"status": "affected", "version": "17.4.1c"}, {"status": "affected", "version": "17.18.1y"}], "defaultStatus": "unknown"}]}], "published": "2026-08-05T17:16:46.643", "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-snmp-dos-ZAqNm4MD", "source": "psirt@cisco.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "psirt@cisco.com", "description": [{"lang": "en", "value": "CWE-772"}]}], "descriptions": [{"lang": "en", "value": "A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.\r\n\r\nThis vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versions of SNMP — Versions 1, 2c, and 3. An attacker could exploit this vulnerability by sending a malformed SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly. The attacker must have the SNMPv1 or v2c read-only or read-write community string or valid SNMPv3 user credentials on the affected device."}], "lastModified": "2026-08-06T15:44:56.043", "sourceIdentifier": "psirt@cisco.com"}