# CVE-2026-20124

## Summary

- **CVE ID:** CVE-2026-20124
- **Severity:** HIGH
- **CVSS Score:** 7.7 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H)
- **CWE:** CWE-772
- **Published:** Aug 5, 2026
- **Last Modified:** Aug 5, 2026

## Description

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.

## Affected Products

- Cisco — Cisco IOS XE Software (17.2.1a)
- Cisco — Cisco IOS XE Software (3.18.7SP)
- Cisco — Cisco IOS XE Software (16.12.1y)
- Cisco — Cisco IOS XE Software (16.12.3s)
- Cisco — Cisco IOS XE Software (16.7.1b)
- Cisco — Cisco IOS XE Software (16.6.2)
- Cisco — Cisco IOS XE Software (16.6.5)
- Cisco — Cisco IOS XE Software (16.12.1w)
- Cisco — Cisco IOS XE Software (3.18.4S)
- Cisco — Cisco IOS XE Software (16.9.1d)
- Cisco — Cisco IOS XE Software (17.3.1)
- Cisco — Cisco IOS XE Software (16.9.4c)
- Cisco — Cisco IOS XE Software (16.7.1)
- Cisco — Cisco IOS XE Software (17.2.1)
- Cisco — Cisco IOS XE Software (16.6.8)
- Cisco — Cisco IOS XE Software (16.9.1b)
- Cisco — Cisco IOS XE Software (3.16.8S)
- Cisco — Cisco IOS XE Software (16.9.2s)
- Cisco — Cisco IOS XE Software (16.12.4)
- Cisco — Cisco IOS XE Software (16.12.3a)
- Cisco — Cisco IOS XE Software (17.1.1s)
- Cisco — Cisco IOS XE Software (16.11.1a)
- Cisco — Cisco IOS XE Software (16.7.2)
- Cisco — Cisco IOS XE Software (16.11.1b)
- Cisco — Cisco IOS XE Software (16.9.1s)
- Cisco — Cisco IOS XE Software (16.9.3h)
- Cisco — Cisco IOS XE Software (16.9.1c)
- Cisco — Cisco IOS XE Software (16.6.5a)
- Cisco — Cisco IOS XE Software (16.6.3)
- Cisco — Cisco IOS XE Software (16.10.1f)
- Cisco — Cisco IOS XE Software (17.2.1v)
- Cisco — Cisco IOS XE Software (16.8.1e)
- Cisco — Cisco IOS XE Software (16.9.3a)
- Cisco — Cisco IOS XE Software (16.12.1a)
- Cisco — Cisco IOS XE Software (16.12.1x)
- Cisco — Cisco IOS XE Software (3.16.10aS)
- Cisco — Cisco IOS XE Software (16.6.4s)
- Cisco — Cisco IOS XE Software (16.10.1c)
- Cisco — Cisco IOS XE Software (16.12.3)
- Cisco — Cisco IOS XE Software (16.11.2)
- Cisco — Cisco IOS XE Software (16.6.5b)
- Cisco — Cisco IOS XE Software (16.12.2s)
- Cisco — Cisco IOS XE Software (16.10.1b)
- Cisco — Cisco IOS XE Software (16.7.3)
- Cisco — Cisco IOS XE Software (16.6.7)
- Cisco — Cisco IOS XE Software (16.9.6)
- Cisco — Cisco IOS XE Software (16.9.2)
- Cisco — Cisco IOS XE Software (3.16.10S)
- Cisco — Cisco IOS XE Software (16.10.1)
- Cisco — Cisco IOS XE Software (16.12.1t)
- Cisco — Cisco IOS XE Software (3.18.3bSP)
- Cisco — Cisco IOS XE Software (3.13.9S)
- Cisco — Cisco IOS XE Software (3.18.3aSP)
- Cisco — Cisco IOS XE Software (3.18.5SP)
- Cisco — Cisco IOS XE Software (16.9.1)
- Cisco — Cisco IOS XE Software (16.8.1a)
- Cisco — Cisco IOS XE Software (3.18.8aSP)
- Cisco — Cisco IOS XE Software (16.9.3s)
- Cisco — Cisco IOS XE Software (16.6.7a)
- Cisco — Cisco IOS XE Software (16.12.2)
- Cisco — Cisco IOS XE Software (16.11.1)
- Cisco — Cisco IOS XE Software (16.9.3)
- Cisco — Cisco IOS XE Software (16.11.1s)
- Cisco — Cisco IOS XE Software (16.12.1)
- Cisco — Cisco IOS XE Software (3.16.9S)
- Cisco — Cisco IOS XE Software (17.1.1)
- Cisco — Cisco IOS XE Software (17.1.2)
- Cisco — Cisco IOS XE Software (16.10.1d)
- Cisco — Cisco IOS XE Software (17.1.1t)
- Cisco — Cisco IOS XE Software (16.9.4)
- Cisco — Cisco IOS XE Software (16.8.3)
- Cisco — Cisco IOS XE Software (16.12.2t)
- Cisco — Cisco IOS XE Software (16.9.5)
- Cisco — Cisco IOS XE Software (3.16.7S)
- Cisco — Cisco IOS XE Software (16.8.1s)
- Cisco — Cisco IOS XE Software (16.10.1e)
- Cisco — Cisco IOS XE Software (16.8.2)
- Cisco — Cisco IOS XE Software (16.6.4)
- Cisco — Cisco IOS XE Software (16.8.1b)
- Cisco — Cisco IOS XE Software (16.10.1a)
- Cisco — Cisco IOS XE Software (16.12.1z)
- Cisco — Cisco IOS XE Software (16.8.1c)
- Cisco — Cisco IOS XE Software (16.9.1a)
- Cisco — Cisco IOS XE Software (3.16.7aS)
- Cisco — Cisco IOS XE Software (16.9.5f)
- Cisco — Cisco IOS XE Software (16.6.4a)
- Cisco — Cisco IOS XE Software (16.10.1g)
- Cisco — Cisco IOS XE Software (3.13.10S)
- Cisco — Cisco IOS XE Software (16.8.1)
- Cisco — Cisco IOS XE Software (16.6.6)
- Cisco — Cisco IOS XE Software (16.9.2a)
- Cisco — Cisco IOS XE Software (16.8.1d)
- Cisco — Cisco IOS XE Software (16.10.3)
- Cisco — Cisco IOS XE Software (3.18.4SP)
- Cisco — Cisco IOS XE Software (3.18.6SP)
- Cisco — Cisco IOS XE Software (3.18.3SP)
- Cisco — Cisco IOS XE Software (16.7.1a)
- Cisco — Cisco IOS XE Software (16.11.1c)
- Cisco — Cisco IOS XE Software (16.10.1s)
- Cisco — Cisco IOS XE Software (17.2.1r)
- Cisco — Cisco IOS XE Software (3.16.7bS)
- Cisco — Cisco IOS XE Software (17.1.1a)
- Cisco — Cisco IOS XE Software (16.10.2)
- Cisco — Cisco IOS XE Software (16.12.2a)
- Cisco — Cisco IOS XE Software (3.16.6bS)
- Cisco — Cisco IOS XE Software (16.12.1c)
- Cisco — Cisco IOS XE Software (16.12.1s)
- Cisco — Cisco IOS XE Software (16.7.4)
- Cisco — Cisco IOS XE Software (3.18.9SP)
- Cisco — Cisco IOS XE Software (17.2.2)
- Cisco — Cisco IOS XE Software (16.9.8)
- Cisco — Cisco IOS XE Software (16.9.7)
- Cisco — Cisco IOS XE Software (17.1.3)
- Cisco — Cisco IOS XE Software (17.3.1a)
- Cisco — Cisco IOS XE Software (17.3.2a)
- Cisco — Cisco IOS XE Software (16.12.5)
- Cisco — Cisco IOS XE Software (17.3.1w)
- Cisco — Cisco IOS XE Software (17.3.2)
- Cisco — Cisco IOS XE Software (17.4.1)
- Cisco — Cisco IOS XE Software (16.12.4a)
- Cisco — Cisco IOS XE Software (17.4.1a)
- Cisco — Cisco IOS XE Software (3.16.10bS)
- Cisco — Cisco IOS XE Software (17.3.1x)
- Cisco — Cisco IOS XE Software (17.3.3)
- Cisco — Cisco IOS XE Software (16.6.9)
- Cisco — Cisco IOS XE Software (17.2.3)
- Cisco — Cisco IOS XE Software (17.5.1)
- Cisco — Cisco IOS XE Software (16.12.1z1)
- Cisco — Cisco IOS XE Software (16.12.5a)
- Cisco — Cisco IOS XE Software (17.4.1b)
- Cisco — Cisco IOS XE Software (17.3.1z)
- Cisco — Cisco IOS XE Software (16.12.5b)
- Cisco — Cisco IOS XE Software (17.4.2)
- Cisco — Cisco IOS XE Software (17.3.3a)
- Cisco — Cisco IOS XE Software (17.3.5)
- Cisco — Cisco IOS XE Software (17.3.4)
- Cisco — Cisco IOS XE Software (17.5.1a)
- Cisco — Cisco IOS XE Software (16.12.6)
- Cisco — Cisco IOS XE Software (17.6.1)
- Cisco — Cisco IOS XE Software (16.12.1z2)
- Cisco — Cisco IOS XE Software (16.6.10)
- Cisco — Cisco IOS XE Software (17.3.4a)
- Cisco — Cisco IOS XE Software (17.6.1a)
- Cisco — Cisco IOS XE Software (17.7.1)
- Cisco — Cisco IOS XE Software (17.6.1x)
- Cisco — Cisco IOS XE Software (17.6.2)
- Cisco — Cisco IOS XE Software (16.12.6a)
- Cisco — Cisco IOS XE Software (17.3.4c)
- Cisco — Cisco IOS XE Software (17.4.2a)
- Cisco — Cisco IOS XE Software (17.3.4b)
- Cisco — Cisco IOS XE Software (17.7.1a)
- Cisco — Cisco IOS XE Software (16.12.7)
- Cisco — Cisco IOS XE Software (17.8.1a)
- Cisco — Cisco IOS XE Software (17.6.3a)
- Cisco — Cisco IOS XE Software (17.6.3)
- Cisco — Cisco IOS XE Software (17.7.2)
- Cisco — Cisco IOS XE Software (17.7.1b)
- Cisco — Cisco IOS XE Software (17.9.1w)
- Cisco — Cisco IOS XE Software (17.3.5a)
- Cisco — Cisco IOS XE Software (17.6.1z)
- Cisco — Cisco IOS XE Software (16.12.8)
- Cisco — Cisco IOS XE Software (17.8.1)
- Cisco — Cisco IOS XE Software (17.9.1)
- Cisco — Cisco IOS XE Software (17.6.4)
- Cisco — Cisco IOS XE Software (17.3.5b)
- Cisco — Cisco IOS XE Software (17.9.1a)
- Cisco — Cisco IOS XE Software (17.3.6)
- Cisco — Cisco IOS XE Software (17.10.1)
- Cisco — Cisco IOS XE Software (16.9.8a)
- Cisco — Cisco IOS XE Software (17.6.1z1)
- Cisco — Cisco IOS XE Software (17.10.1a)
- Cisco — Cisco IOS XE Software (17.9.2)
- Cisco — Cisco IOS XE Software (17.6.5)
- Cisco — Cisco IOS XE Software (17.9.1x)
- Cisco — Cisco IOS XE Software (17.9.1y)
- Cisco — Cisco IOS XE Software (16.9.8b)
- Cisco — Cisco IOS XE Software (17.3.7)
- Cisco — Cisco IOS XE Software (17.9.2a)
- Cisco — Cisco IOS XE Software (17.9.3)
- Cisco — Cisco IOS XE Software (16.12.9)
- Cisco — Cisco IOS XE Software (17.11.1)
- Cisco — Cisco IOS XE Software (17.10.1b)
- Cisco — Cisco IOS XE Software (17.6.6)
- Cisco — Cisco IOS XE Software (17.9.1x1)
- Cisco — Cisco IOS XE Software (17.11.1a)
- Cisco — Cisco IOS XE Software (17.9.3a)
- Cisco — Cisco IOS XE Software (17.12.1)
- Cisco — Cisco IOS XE Software (17.3.8)
- Cisco — Cisco IOS XE Software (17.9.4)
- Cisco — Cisco IOS XE Software (16.12.10)
- Cisco — Cisco IOS XE Software (17.12.1w)
- Cisco — Cisco IOS XE Software (17.9.1y1)
- Cisco — Cisco IOS XE Software (17.12.1a)
- Cisco — Cisco IOS XE Software (17.9.5)
- Cisco — Cisco IOS XE Software (17.13.1)
- Cisco — Cisco IOS XE Software (17.12.1x)
- Cisco — Cisco IOS XE Software (17.12.2)
- Cisco — Cisco IOS XE Software (17.14.1)
- Cisco — Cisco IOS XE Software (17.9.4a)
- Cisco — Cisco IOS XE Software (17.3.8a)
- Cisco — Cisco IOS XE Software (17.6.6a)
- Cisco — Cisco IOS XE Software (17.6.5a)
- Cisco — Cisco IOS XE Software (17.6.7)
- Cisco — Cisco IOS XE Software (16.12.10a)
- Cisco — Cisco IOS XE Software (17.15.1)
- Cisco — Cisco IOS XE Software (17.13.1a)
- Cisco — Cisco IOS XE Software (17.12.2a)
- Cisco — Cisco IOS XE Software (16.12.11)
- Cisco — Cisco IOS XE Software (17.12.3)
- Cisco — Cisco IOS XE Software (17.12.1y)
- Cisco — Cisco IOS XE Software (17.12.1z)
- Cisco — Cisco IOS XE Software (17.9.5a)
- Cisco — Cisco IOS XE Software (17.14.1a)
- Cisco — Cisco IOS XE Software (17.9.5b)
- Cisco — Cisco IOS XE Software (17.6.8)
- Cisco — Cisco IOS XE Software (16.12.12)
- Cisco — Cisco IOS XE Software (17.12.4)
- Cisco — Cisco IOS XE Software (17.9.6)
- Cisco — Cisco IOS XE Software (17.17.1)
- Cisco — Cisco IOS XE Software (17.16.1)
- Cisco — Cisco IOS XE Software (17.15.1w)
- Cisco — Cisco IOS XE Software (17.12.3a)
- Cisco — Cisco IOS XE Software (17.9.5c)
- Cisco — Cisco IOS XE Software (17.15.1a)
- Cisco — Cisco IOS XE Software (17.12.1z1)
- Cisco — Cisco IOS XE Software (17.15.2)
- Cisco — Cisco IOS XE Software (17.15.1b)
- Cisco — Cisco IOS XE Software (17.9.5d)
- Cisco — Cisco IOS XE Software (17.15.1x)
- Cisco — Cisco IOS XE Software (17.9.6a)
- Cisco — Cisco IOS XE Software (17.12.1z2)
- Cisco — Cisco IOS XE Software (17.6.8a)
- Cisco — Cisco IOS XE Software (17.16.1a)
- Cisco — Cisco IOS XE Software (16.12.13)
- Cisco — Cisco IOS XE Software (17.15.3)
- Cisco — Cisco IOS XE Software (17.9.7)
- Cisco — Cisco IOS XE Software (17.12.5)
- Cisco — Cisco IOS XE Software (17.15.1y)
- Cisco — Cisco IOS XE Software (17.9.5e)
- Cisco — Cisco IOS XE Software (17.12.4a)
- Cisco — Cisco IOS XE Software (17.15.2a)
- Cisco — Cisco IOS XE Software (17.15.2c)
- Cisco — Cisco IOS XE Software (17.15.2b)
- Cisco — Cisco IOS XE Software (17.12.1z3)
- Cisco — Cisco IOS XE Software (17.9.5f)
- Cisco — Cisco IOS XE Software (17.12.4b)
- Cisco — Cisco IOS XE Software (17.12.5a)
- Cisco — Cisco IOS XE Software (17.18.1)
- Cisco — Cisco IOS XE Software (17.12.6)
- Cisco — Cisco IOS XE Software (17.12.1z4)
- Cisco — Cisco IOS XE Software (17.9.8)
- Cisco — Cisco IOS XE Software (17.9.7a)
- Cisco — Cisco IOS XE Software (17.15.3a)
- Cisco — Cisco IOS XE Software (17.15.4)
- Cisco — Cisco IOS XE Software (17.12.5b)
- Cisco — Cisco IOS XE Software (17.15.3b)
- Cisco — Cisco IOS XE Software (16.12.14)
- Cisco — Cisco IOS XE Software (17.9.7b)
- Cisco — Cisco IOS XE Software (17.12.5c)
- Cisco — Cisco IOS XE Software (17.18.1a)
- Cisco — Cisco IOS XE Software (17.15.4a)
- Cisco — Cisco IOS XE Software (17.18.2)
- Cisco — Cisco IOS XE Software (17.18.1w)
- Cisco — Cisco IOS XE Software (17.15.4b)
- Cisco — Cisco IOS XE Software (17.12.6a)
- Cisco — Cisco IOS XE Software (17.15.4c)
- Cisco — Cisco IOS XE Software (17.9.9)
- Cisco — Cisco IOS XE Software (17.12.5d)
- Cisco — Cisco IOS XE Software (16.12.15)
- Cisco — Cisco IOS XE Software (17.15.4s1)
- Cisco — Cisco IOS XE Software (17.12.1z5)
- Cisco — Cisco IOS XE Software (17.18.1x)
- Cisco — Cisco IOS XE Software (17.12.1z6)
- Cisco — Cisco IOS XE Software (17.15.4d)
- Cisco — Cisco IOS XE Software (17.12.6b)
- Cisco — Cisco IOS XE Software (17.4.1c)
- Cisco — Cisco IOS XE Software (17.18.1y)

## References

- [CNA](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-snmp-dos-ZAqNm4MD)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.34%
- **EPSS Percentile:** 27.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._