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Cisco released security updates for 14 vulnerabilities in Cisco IOS and Cisco IOS XE, including the actively exploited zero-day CVE-2025-20352. The flaw is a stack overflow in the SNMP subsystem that can be triggered with crafted SNMP packets over IPv4 or IPv6. Cisco said a remote authenticated attacker can cause a denial of service, while an authenticated attacker with administrator privileges can escalate to remote code execution and full device compromise.
Affected products include unpatched Cisco IOS and IOS XE devices, along with Meraki MS390 and Cisco Catalyst 9300 Series switches running Meraki CS 17 or earlier when SNMP is enabled and vulnerable OIDs have not been explicitly disabled. Cisco urged organizations to use its Software Checker to identify exposure and apply fixes immediately; where patching is not yet possible, recommended mitigations include restricting SNMP access to trusted sources, disabling SNMP, or disabling vulnerable OIDs through device configuration.
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1 event from the most recent confirmed update back to the earliest known activity.
Cisco released security updates for 14 vulnerabilities in Cisco IOS and Cisco IOS XE, including CVE-2025-20352, a zero-day in the SNMP subsystem that was being actively exploited. The updates addressed affected Cisco IOS, IOS XE, Meraki MS390, and Catalyst 9300 devices under the conditions described by Cisco and CSIRT.SK.
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A critical security vulnerability, CVE-2025-20352, has been identified in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE software, affecting a wide range of Cisco networking devices. This stack overflow flaw allows remote attackers with valid SNMP credentials to send specially crafted SNMP packets over IPv4 or IPv6, potentially causing denial-of-service (DoS) by forcing device reloads or, in more severe cases, enabling remote code execution as root. The vulnerability impacts all SNMP versions (v1, v2c, v3) and has been confirmed to affect both legacy and modern modular Cisco operating systems, including Meraki MS390 and Catalyst 9300 Series Switches running Meraki CS 17 and earlier. Reports indicate that up to 2 million devices globally, including those operated by ISPs and cloud providers, are potentially exposed to this vulnerability. The flaw was discovered during a Cisco Technical Assistance Center (TAC) support case and has already been exploited in the wild, prompting its addition to the CISA Known Exploited Vulnerabilities (KEV) catalog on September 29th, 2025. The exploitation of this vulnerability represents a significant escalation, as attackers have demonstrated the ability to gain administrator-level credentials and full device compromise. Rockwell Automation has issued an advisory confirming that its Lifecycle Services, specifically the Industrial Data Center (IDC) with Cisco Switching (Generations 1–5), are affected by this vulnerability. Rockwell has provided guidance on corrected software versions and available workarounds to mitigate the risk. The vulnerability poses a substantial threat to the backbone of enterprise, industrial, and service provider networks, given the widespread deployment of affected Cisco devices. Cisco’s response to the incident was initiated only after evidence of active exploitation emerged, underscoring the urgency of patching and mitigation. Organizations are strongly advised to update to the corrected Cisco software versions as soon as possible and to implement any recommended workarounds to reduce exposure. The incident highlights the ongoing risks associated with SNMP-enabled network infrastructure and the importance of credential management and network segmentation. Security teams should prioritize the identification of vulnerable devices and monitor for signs of exploitation. The rapid exploitation and large attack surface associated with CVE-2025-20352 make it a high-priority threat for organizations relying on Cisco networking equipment.
Jun 29, 2026
Multiple vulnerabilities in **Cisco IOS** and **Cisco IOS XE** devices have exposed routers, switches, access points, and Catalyst 9000 platforms to severe compromise, including **remote code execution**, **denial of service**, **access control bypass**, **privilege escalation**, **secure boot bypass**, **cross-site scripting**, and memory corruption. Traficom highlighted newly disclosed flaws such as `CVE-2025-20334` and `CVE-2025-20363`, which may allow arbitrary code execution, and urged organizations to update affected products in line with Cisco’s version-specific advisories. The warning follows earlier real-world attacks against internet-exposed Cisco IOS XE Web GUI instances, where attackers exploited `CVE-2023-20198` and `CVE-2023-20273` to create unauthorized administrator accounts, install a backdoor implant, and seize full control of devices. Cisco Talos reported the campaign affected exposed systems internationally, with tens of thousands of vulnerable devices identified online, while Finnish authorities said some domestic devices had already been backdoored and advised restricting Web GUI access to trusted networks or removing public internet exposure entirely.
Jun 29, 2026
Cisco disclosed a broad set of security flaws across enterprise products, including critical unauthenticated remote code execution, arbitrary command execution, and authentication bypass vulnerabilities affecting **Smart Software Manager On-Prem**, **Integrated Management Controller**, **Nexus Dashboard Fabric Controller**, and **Secure Firewall Management Center**. Additional high- and medium-severity issues impact **IOS XE** and other Cisco platforms, enabling denial of service, privilege escalation, arbitrary file write, server-side request forgery, secure boot bypass, sensitive information exposure, and cross-site scripting. Many of the vulnerabilities affect web-based management interfaces and network-facing services, raising the risk to remotely reachable administrative systems. One of the most severe issues, **`CVE-2026-20223`**, affects **Cisco Secure Workload** and allows an unauthenticated attacker to bypass REST API authentication and perform administrative actions. The flaw, tracked as **CWE-306** and rated **CVSS 10.0**, can expose configuration data, alter microsegmentation policies, and enable cross-tenant access with Site Admin-level impact in both SaaS and on-premises deployments. Cisco said no workaround is available and released fixes in versions **3.10.8.3** and **4.0.3.17**; reporting cited no known active exploitation or public proof-of-concept at the time.
Jul 14, 2026