Cisco Meraki Firmware: Buffer overflow in multiple product lines
Summary
A memory buffer flaw (CWE-119) in Cisco Meraki firmware affects several product lines, including MX, MR, MS, MV, MG and Campus Gateway devices. Cisco rates it 9.6 (Critical) and says an attacker with adjacent network access and no privileges or user interaction could affect confidentiality, integrity and availability. Cisco reports no known exploitation and no workarounds.
Affected
- Cisco Meraki MX Security and SD-WAN Appliances (firmware 16.2 to 18.1 and later lines as listed in the advisory)
- Cisco Meraki MR Wireless Access Points (for example 30.6, 32.1.7, 32.2.3, 33.1.1, 33.1.2)
- Cisco Meraki MV Smart Cameras (firmware 4.20 to 6.0)
- Cisco Meraki MS Series Switches and MG Cellular Gateways (see advisory)
- Campus Gateway (CG 33.1.3 per CVE record)
- Version ranges: verify each model in the Cisco advisory table, as the extracted list is incomplete.
Fixed in
- MX: 18.1 (18.107.14 where offered), 19.2 (19.2.9, Z3 devices), 26.1 (26.1.7), 26.2 (26.2.3)
- MR: 30.7.3, 31.1.8.1, 32.2.5, 33.1.3
- MS: 18.1.9, IOS XE 17.15.6, 17.18.4.1, 26.1.2
- MG: 4.1.4 (MG21/E only), 26.1.4
- MV: 8.0
- Campus Gateway: 32.2.5 (late October 2026), 33.1.4 (mid-November 2026)
- Some fixed releases were not yet available at publication; check the advisory for current availability.
Workaround
Unknown. Cisco states there are no workarounds that address these vulnerabilities.
Exploitation
- Cisco PSIRT is not aware of public announcements or malicious use.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
- No public proof of concept identified.
Our recommendation
- Inventory all Meraki devices (MX, MR, MS, MV, MG, Campus Gateway) and their current firmware versions in the Meraki Dashboard.
- Apply the fixed release for each model as soon as it is available, testing first on a pilot device.
- Until patched, limit management access and separate guest, IoT and camera networks from management traffic.
- Monitor devices for unusual behaviour and check the advisory for updates.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Cisco Security Advisory cisco-sa-hardening-meraki-os-drbEX9GH sec.cloudapps.cisco.com
- Cisco Security Advisory (Support docs) www.cisco.com
- OpenCVE CVE-2026-76464 app.opencve.io
- Cisco Community advisory discussion community.cisco.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 23:06.
Original description (NVD)
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco networking engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by this CVE-2026-76464 are related to buffer management issues that are grouped under the Common Weakness Enumeration (CWE) CWE-119.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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