--- id: "CVE-2025-20352" kind: "vulnerability" aliases: ["CVE-2025-20352"] title: "A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE\u2026" severity: "high" cvss: 7.7 epss: null exploited: true status: "open" category: "infrastructure" products: [{"name": "Cisco IOS and IOS XE", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.9.1", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.9.2", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.9.3", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.9.4", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.1", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.2", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.3", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.3a", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.3b", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.4", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.5", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.10.6", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.11.1a", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.1b", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.1d", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.1e", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.2r", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.3", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.4", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.4a", "ecosystem": "vendor"}, {"name": "cisco ios xe sd-wan", "fixed": [], "affected": "= 16.12.5", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.0e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.0sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.1e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.1sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.2e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.2sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.3e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.3sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.4sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.5sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.6sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.7sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.5.8sq", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.0e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.1e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.2ae", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.2e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.3e", "ecosystem": "vendor"}, {"name": "cisco ios xe", "fixed": [], "affected": "= 3.6.4e", "ecosystem": "vendor"}] ecosystems: ["vendor"] tags: ["cisco", "exploited", "infrastructure", "ios", "ios-xe", "network-devices", "snmp"] not_affected_if: ["snmp-disabled"] published_at: "2025-09-24T18:15:36+00:00" first_seen_at: "2026-10-23T19:11:51+00:00" updated_at: "2026-10-23T23:44:51+00:00" sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-20352", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-20352", "first_seen_at": "2026-10-23T23:44:51+00:00"}] --- # A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE… Cisco IOS and IOS XE have a stack-based buffer overflow in the SNMP subsystem. An attacker with low privileges can reload the device for denial of service, and a high-privileged attacker can run arbitrary code as root and take full control. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - vendor:Cisco IOS and IOS XE affected ? fixed ? - vendor:cisco ios xe sd-wan affected = 16.9.1 fixed ? - vendor:cisco ios xe sd-wan affected = 16.9.2 fixed ? - vendor:cisco ios xe sd-wan affected = 16.9.3 fixed ? - vendor:cisco ios xe sd-wan affected = 16.9.4 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.1 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.2 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.3 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.3a fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.3b fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.4 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.5 fixed ? - vendor:cisco ios xe sd-wan affected = 16.10.6 fixed ? - vendor:cisco ios xe sd-wan affected = 16.11.1a fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.1b fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.1d fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.1e fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.2r fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.3 fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.4 fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.4a fixed ? - vendor:cisco ios xe sd-wan affected = 16.12.5 fixed ? - vendor:cisco ios xe affected = 3.5.0e fixed ? - vendor:cisco ios xe affected = 3.5.0sq fixed ? - vendor:cisco ios xe affected = 3.5.1e fixed ? - vendor:cisco ios xe affected = 3.5.1sq fixed ? - vendor:cisco ios xe affected = 3.5.2e fixed ? - vendor:cisco ios xe affected = 3.5.2sq fixed ? - vendor:cisco ios xe affected = 3.5.3e fixed ? - vendor:cisco ios xe affected = 3.5.3sq fixed ? - vendor:cisco ios xe affected = 3.5.4sq fixed ? - vendor:cisco ios xe affected = 3.5.5sq fixed ? - vendor:cisco ios xe affected = 3.5.6sq fixed ? - vendor:cisco ios xe affected = 3.5.7sq fixed ? - vendor:cisco ios xe affected = 3.5.8sq fixed ? - vendor:cisco ios xe affected = 3.6.0e fixed ? - vendor:cisco ios xe affected = 3.6.1e fixed ? - vendor:cisco ios xe affected = 3.6.2ae fixed ? - vendor:cisco ios xe affected = 3.6.2e fixed ? - vendor:cisco ios xe affected = 3.6.3e fixed ? - vendor:cisco ios xe affected = 3.6.4e fixed ? ## How to check Check the device's IOS or IOS XE version with 'show version' and compare it against the Cisco advisory for this CVE; check whether SNMP is enabled with 'show running-config | include snmp'. ## Fix Apply the Cisco fix per the vendor advisory; if no fix is available, follow the CISA mitigation guidance or stop using the affected product. ## Timeline - 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-20352 - 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-20352 ## From the sources A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks. This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. Note: This vulnerability affects all versions of SNMP. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_