CVE-2017-6736: Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 3 Mar 2022, 1,690 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 70.4%
EPSS score, percentile 99.4 of all scored records
- How severe?
- 8.8 High
CVSS v3.0 base score, given by the CNA
- What should I do?
CISA deadline 24 Mar 2022. Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 12.1(3a)XI9
- 12.1(3)XI
- 12.1(3a)XI8
- 12.1(3a)XI3
- 12.1(3a)XI1
- 12.1(3a)XI7
and 7 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 24 March 2022.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 12.1(3a)XI9 |
| Affected | 12.1(3)XI |
| Affected | 12.1(3a)XI8 |
| Affected | 12.1(3a)XI3 |
| Affected | 12.1(3a)XI1 |
| Affected | 12.1(3a)XI7 |
| Affected | 12.1(3a)XI6 |
| Affected | 12.1(3a)XI4 |
| Affected | 12.1(3a)XI2 |
| Affected | 12.1(3a)XI5 |
| Affected | 12.0(5)S |
| Affected | 12.0(11)S6 |
And 1732 more version entries in the CVE record.
| Status | Versions |
|---|---|
| Affected | unspecified |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE contains a vulnerability that could allow an authenticated, remote attacker to remotely execute code.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2017-6736 to its Known Exploited Vulnerabilities (KEV) catalog on 3 Mar 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 24 Mar 2022.
- The CVE record was published on 17 Jul 2017, 1,690 days before it was added to KEV.
- The CVE record carries a CVSS v3.0 base score of 8.8 (High), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 70.4% (percentile 99.4), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an affected system to reload. An attacker could exploit these vulnerabilities by sending a crafted SNMP packet to an affected system via IPv4 or IPv6. Only traffic directed to an affected system can be used to exploit these vulnerabilities. The vulnerabilities are due to a buffer overflow condition in the SNMP subsystem of the affected software. The vulnerabilities affect all versions of SNMP - Versions 1, 2c, and 3. To exploit these vulnerabilities via SNMP Version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP Version 3, the attacker must have user credentials for the affected system. A successful exploit could allow the attacker to execute arbitrary code and obtain full control of the affected system or cause the affected system to reload. Customers are advised to apply the workaround as contained in the Workarounds section below. Fixed software information is available via the Cisco IOS Software Checker. All devices that have enabled SNMP and have not explicitly excluded the affected MIBs or OIDs should be considered vulnerable. There are workarounds that address these vulnerabilities.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 17 Jul 2017 | CVE record published |
| 3 Mar 2022 | Added to CISA KEV |
| 24 Mar 2022 | CISA due date for the required action |
| 21 Oct 2025 | CVE record last updated |
References
More exploited Cisco vulnerabilities
- CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
- CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
- CVE-2026-76461: Cisco Secure Email Gateway SQL Injection Vulnerability
- CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
- CVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability