Answer in brief
CVE-2026-20124 records a High severity (CVSS 7.7) vulnerability in Cisco IOS XE Software SNMP Denial of Service Vulnerability. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco IOS XE Software (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco IOS XE Software (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco IOS XE Softwaregeneric | 17.2.1a || 3.18.7SP || 16.12.1y || 16.12.3s || 16.7.1b || 16.6.2 || 16.6.5 || 16.12.1w || 3.18.4S || 16.9.1d || 17.3.1 || 16.9.4c || 16.7.1 || 17.2.1 || 16.6.8 || 16.9.1b || 3.16.8S || 16.9.2s || 16.12.4 || 16.12.3a || 17.1.1s || 16.11.1a || 16.7.2 || 16.11.1b || 16.9.1s || 16.9.3h || 16.9.1c || 16.6.5a || 16.6.3 || 16.10.1f || 17.2.1v || 16.8.1e || 16.9.3a || 16.12.1a || 16.12.1x || 3.16.10aS || 16.6.4s || 16.10.1c || 16.12.3 || 16.11.2 || 16.6.5b || 16.12.2s || 16.10.1b || 16.7.3 || 16.6.7 || 16.9.6 || 16.9.2 || 3.16.10S || 16.10.1 || 16.12.1t || 3.18.3bSP || 3.13.9S || 3.18.3aSP || 3.18.5SP || 16.9.1 || 16.8.1a || 3.18.8aSP || 16.9.3s || 16.6.7a || 16.12.2 || 16.11.1 || 16.9.3 || 16.11.1s || 16.12.1 || 3.16.9S || 17.1.1 || 17.1.2 || 16.10.1d || 17.1.1t || 16.9.4 || 16.8.3 || 16.12.2t || 16.9.5 || 3.16.7S || 16.8.1s || 16.10.1e || 16.8.2 || 16.6.4 || 16.8.1b || 16.10.1a || 16.12.1z || 16.8.1c || 16.9.1a || 3.16.7aS || 16.9.5f || 16.6.4a || 16.10.1g || 3.13.10S || 16.8.1 || 16.6.6 || 16.9.2a || 16.8.1d || 16.10.3 || 3.18.4SP || 3.18.6SP || 3.18.3SP || 16.7.1a || 16.11.1c || 16.10.1s || 17.2.1r || 3.16.7bS || 17.1.1a || 16.10.2 || 16.12.2a || 3.16.6bS || 16.12.1c || 16.12.1s || 16.7.4 || 3.18.9SP || 17.2.2 || 16.9.8 || 16.9.7 || 17.1.3 || 17.3.1a || 17.3.2a || 16.12.5 || 17.3.1w || 17.3.2 || 17.4.1 || 16.12.4a || 17.4.1a || 3.16.10bS || 17.3.1x || 17.3.3 || 16.6.9 || 17.2.3 || 17.5.1 || 16.12.1z1 || 16.12.5a || 17.4.1b || 17.3.1z || 16.12.5b || 17.4.2 || 17.3.3a || 17.3.5 || 17.3.4 || 17.5.1a || 16.12.6 || 17.6.1 || 16.12.1z2 || 16.6.10 || 17.3.4a || 17.6.1a || 17.7.1 || 17.6.1x || 17.6.2 || 16.12.6a || 17.3.4c || 17.4.2a || 17.3.4b || 17.7.1a || 16.12.7 || 17.8.1a || 17.6.3a || 17.6.3 || 17.7.2 || 17.7.1b || 17.9.1w || 17.3.5a || 17.6.1z || 16.12.8 || 17.8.1 || 17.9.1 || 17.6.4 || 17.3.5b || 17.9.1a || 17.3.6 || 17.10.1 || 16.9.8a || 17.6.1z1 || 17.10.1a || 17.9.2 || 17.6.5 || 17.9.1x || 17.9.1y || 16.9.8b || 17.3.7 || 17.9.2a || 17.9.3 || 16.12.9 || 17.11.1 || 17.10.1b || 17.6.6 || 17.9.1x1 || 17.11.1a || 17.9.3a || 17.12.1 || 17.3.8 || 17.9.4 || 16.12.10 || 17.12.1w || 17.9.1y1 || 17.12.1a || 17.9.5 || 17.13.1 || 17.12.1x || 17.12.2 || 17.14.1 || 17.9.4a || 17.3.8a || 17.6.6a || 17.6.5a || 17.6.7 || 16.12.10a || 17.15.1 || 17.13.1a || 17.12.2a || 16.12.11 || 17.12.3 || 17.12.1y || 17.12.1z || 17.9.5a || 17.14.1a || 17.9.5b || 17.6.8 || 16.12.12 || 17.12.4 || 17.9.6 || 17.17.1 || 17.16.1 || 17.15.1w || 17.12.3a || 17.9.5c || 17.15.1a || 17.12.1z1 || 17.15.2 || 17.15.1b || 17.9.5d || 17.15.1x || 17.9.6a || 17.12.1z2 || 17.6.8a || 17.16.1a || 16.12.13 || 17.15.3 || 17.9.7 || 17.12.5 || 17.15.1y || 17.9.5e || 17.12.4a || 17.15.2a || 17.15.2c || 17.15.2b || 17.12.1z3 || 17.9.5f || 17.12.4b || 17.12.5a || 17.18.1 || 17.12.6 || 17.12.1z4 || 17.9.8 || 17.9.7a || 17.15.3a || 17.15.4 || 17.12.5b || 17.15.3b || 16.12.14 || 17.9.7b || 17.12.5c || 17.18.1a || 17.15.4a || 17.18.2 || 17.18.1w || 17.15.4b || 17.12.6a || 17.15.4c || 17.9.9 || 17.12.5d || 16.12.15 || 17.15.4s1 || 17.12.1z5 || 17.18.1x || 17.12.1z6 || 17.15.4d || 17.12.6b || 17.4.1c || 17.18.1y | Not reported |
Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-20124 records a High severity (CVSS 7.7) vulnerability in Cisco IOS XE Software SNMP Denial of Service Vulnerability. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco IOS XE Software (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco IOS XE Software (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco IOS XE Softwaregeneric | 17.2.1a || 3.18.7SP || 16.12.1y || 16.12.3s || 16.7.1b || 16.6.2 || 16.6.5 || 16.12.1w || 3.18.4S || 16.9.1d || 17.3.1 || 16.9.4c || 16.7.1 || 17.2.1 || 16.6.8 || 16.9.1b || 3.16.8S || 16.9.2s || 16.12.4 || 16.12.3a || 17.1.1s || 16.11.1a || 16.7.2 || 16.11.1b || 16.9.1s || 16.9.3h || 16.9.1c || 16.6.5a || 16.6.3 || 16.10.1f || 17.2.1v || 16.8.1e || 16.9.3a || 16.12.1a || 16.12.1x || 3.16.10aS || 16.6.4s || 16.10.1c || 16.12.3 || 16.11.2 || 16.6.5b || 16.12.2s || 16.10.1b || 16.7.3 || 16.6.7 || 16.9.6 || 16.9.2 || 3.16.10S || 16.10.1 || 16.12.1t || 3.18.3bSP || 3.13.9S || 3.18.3aSP || 3.18.5SP || 16.9.1 || 16.8.1a || 3.18.8aSP || 16.9.3s || 16.6.7a || 16.12.2 || 16.11.1 || 16.9.3 || 16.11.1s || 16.12.1 || 3.16.9S || 17.1.1 || 17.1.2 || 16.10.1d || 17.1.1t || 16.9.4 || 16.8.3 || 16.12.2t || 16.9.5 || 3.16.7S || 16.8.1s || 16.10.1e || 16.8.2 || 16.6.4 || 16.8.1b || 16.10.1a || 16.12.1z || 16.8.1c || 16.9.1a || 3.16.7aS || 16.9.5f || 16.6.4a || 16.10.1g || 3.13.10S || 16.8.1 || 16.6.6 || 16.9.2a || 16.8.1d || 16.10.3 || 3.18.4SP || 3.18.6SP || 3.18.3SP || 16.7.1a || 16.11.1c || 16.10.1s || 17.2.1r || 3.16.7bS || 17.1.1a || 16.10.2 || 16.12.2a || 3.16.6bS || 16.12.1c || 16.12.1s || 16.7.4 || 3.18.9SP || 17.2.2 || 16.9.8 || 16.9.7 || 17.1.3 || 17.3.1a || 17.3.2a || 16.12.5 || 17.3.1w || 17.3.2 || 17.4.1 || 16.12.4a || 17.4.1a || 3.16.10bS || 17.3.1x || 17.3.3 || 16.6.9 || 17.2.3 || 17.5.1 || 16.12.1z1 || 16.12.5a || 17.4.1b || 17.3.1z || 16.12.5b || 17.4.2 || 17.3.3a || 17.3.5 || 17.3.4 || 17.5.1a || 16.12.6 || 17.6.1 || 16.12.1z2 || 16.6.10 || 17.3.4a || 17.6.1a || 17.7.1 || 17.6.1x || 17.6.2 || 16.12.6a || 17.3.4c || 17.4.2a || 17.3.4b || 17.7.1a || 16.12.7 || 17.8.1a || 17.6.3a || 17.6.3 || 17.7.2 || 17.7.1b || 17.9.1w || 17.3.5a || 17.6.1z || 16.12.8 || 17.8.1 || 17.9.1 || 17.6.4 || 17.3.5b || 17.9.1a || 17.3.6 || 17.10.1 || 16.9.8a || 17.6.1z1 || 17.10.1a || 17.9.2 || 17.6.5 || 17.9.1x || 17.9.1y || 16.9.8b || 17.3.7 || 17.9.2a || 17.9.3 || 16.12.9 || 17.11.1 || 17.10.1b || 17.6.6 || 17.9.1x1 || 17.11.1a || 17.9.3a || 17.12.1 || 17.3.8 || 17.9.4 || 16.12.10 || 17.12.1w || 17.9.1y1 || 17.12.1a || 17.9.5 || 17.13.1 || 17.12.1x || 17.12.2 || 17.14.1 || 17.9.4a || 17.3.8a || 17.6.6a || 17.6.5a || 17.6.7 || 16.12.10a || 17.15.1 || 17.13.1a || 17.12.2a || 16.12.11 || 17.12.3 || 17.12.1y || 17.12.1z || 17.9.5a || 17.14.1a || 17.9.5b || 17.6.8 || 16.12.12 || 17.12.4 || 17.9.6 || 17.17.1 || 17.16.1 || 17.15.1w || 17.12.3a || 17.9.5c || 17.15.1a || 17.12.1z1 || 17.15.2 || 17.15.1b || 17.9.5d || 17.15.1x || 17.9.6a || 17.12.1z2 || 17.6.8a || 17.16.1a || 16.12.13 || 17.15.3 || 17.9.7 || 17.12.5 || 17.15.1y || 17.9.5e || 17.12.4a || 17.15.2a || 17.15.2c || 17.15.2b || 17.12.1z3 || 17.9.5f || 17.12.4b || 17.12.5a || 17.18.1 || 17.12.6 || 17.12.1z4 || 17.9.8 || 17.9.7a || 17.15.3a || 17.15.4 || 17.12.5b || 17.15.3b || 16.12.14 || 17.9.7b || 17.12.5c || 17.18.1a || 17.15.4a || 17.18.2 || 17.18.1w || 17.15.4b || 17.12.6a || 17.15.4c || 17.9.9 || 17.12.5d || 16.12.15 || 17.15.4s1 || 17.12.1z5 || 17.18.1x || 17.12.1z6 || 17.15.4d || 17.12.6b || 17.4.1c || 17.18.1y | Not reported |
Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.