Status: EXPLOITED | Advisory ID: CVE-2026-20124
| CVE | CVE-2026-20124 |
| CVSS Score / Version | 7.7 (High) / CVSS v3.1 |
| Updated | 2026-09-20 |
| CVSS Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H |
| CVSS Prose | attack vector is network; attack complexity is low; privileges required is low; user interaction is none; scope is changed; confidentiality impact is none; integrity impact is none; availability impact is high. |
| Affected products | Cisco IOS XE |
| Exploitation status | The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory. |
| Classified as | CWE-772 (Missing Release of Resource after Effective Lifetime) |
| Exploitation prediction (EPSS) | 0.50% probability of exploitation in the next 30 days (40% percentile) -- FIRST.org's EPSS model. |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Cisco | IOS XE |
| Subsystems | Industrial Network - Routers/Firewalls |
| Sectors | Critical Manufacturing, Energy, Transportation Systems, Water and Wastewater Systems |
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.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. There is a mitigation that addresses this vulnerability.