CVE Intelligence
CISA KEV High Memory corruption exploit reference

CVE-2017-6736 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

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.

Published Jul 17, 2017 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: cisco

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Mar 3, 2022 Exploit-DB · 1
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (exploitdb)+8
  • EPSS 70.4% (30-day exploitation probability)+15
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Mar 3, 2022
EPSS FIRST
70.35%
ahead of 99% of scored CVEs · Oct 14, 2026
Affects
Cisco
Ios
CVSS base
8.8
High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Mar 24, 2022 — passed 1666 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Cisco Ios).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Cisco Ios version 15.6(2)T2version 12.2(33)SCJ2bversion 12.2(33)SCJ2aversion 12.2(33)SCJ2version 12.2(33)SCJ1aversion 12.2(33)SCJversion 15.3(1)SY2version 15.3(1)SY1
and 290 more version 15.3(1)SYversion 12.2(33)SCJ2cversion 15.6(1)T2version 15.6(2)T1version 15.6(1)T1version 15.6(1)T0aversion 15.6(2)Tversion 15.6(1)Tversion 15.0(2)SQD8version 15.1(3)SVJ2version 15.3(3)JPR1version 15.5(1)SYversion 15.4(1)SY2version 15.4(1)SY1version 15.4(1)SYversion 15.3(3)JPC5version 15.1(3)SVGversion 15.6(3)M2aversion 15.6(3)M2version 15.6(3)M1bversion 15.6(3)M0aversion 15.6(3)M1version 15.6(3)Mversion 12.2(33)SCJ3version 15.5(2)T2version 15.5(3)M3version 15.5(3)M2version 15.5(3)M0aversion 15.5(3)M1version 15.5(3)Mversion 15.5(1)T4version 15.5(2)T4version 15.5(2)T3version 15.0(2)SQD6version 15.5(2)T1version 15.5(1)T3version 15.5(1)T2version 15.5(2)Tversion 15.5(1)T1version 15.5(1)Tversion 15.5(3)S5version 15.5(3)M4aversion 15.0(2)SQD7version 15.0(2)SQD5version 15.0(2)SQD4version 15.0(2)SQD3version 15.0(2)SQD2version 15.0(2)SQD1version 15.0(2)SQDversion 15.3(3)JAA1version 12.2(33)SCI2aversion 12.2(33)SCI3version 12.2(33)SCI2version 12.2(33)SCI1aversion 12.2(33)SCI1version 12.2(33)SCIversion 15.5(3)M5version 15.5(3)M4version 12.3(14)YM8version 12.3(14)YM12version 12.3(14)YM4version 12.3(14)YM3version 12.3(14)YM7version 12.3(14)YM11version 12.3(14)YM9version 12.3(14)YM6version 12.3(14)YM10version 12.3(14)YM13version 12.3(14)YM5version 12.3(14)YM2version 12.1(2)GBversion 12.2(28)SB2version 12.2(28)SBversion 12.2(28)SB10version 12.2(31)SB3xversion 12.2(28)SB11version 12.2(31)SB5version 12.2(31)SB10version 12.2(28)SB3version 12.2(31)SB15version 12.2(28)SB5version 12.2(31)SB11version 12.2(28)SB12version 12.2(31)SB7version 12.2(31)SB6version 12.2(28)SB6version 12.2(31)SB17version 12.2(28)SB8version 12.2(31)SB13version 12.2(31)SB9version 12.2(28)SB4version 12.2(31)SB16version 12.2(31)SB12version 12.2(31)SB20version 12.2(28)SB7version 12.2(28)SB9version 12.2(31)SB8version 12.2(31)SB3version 12.2(31)SB18version 12.2(31)SB2version 12.2(31)SB14version 12.2(31)SB19version 12.2(28)SB13version 12.2(31)SB21version 12.2(33)SRAversion 12.2(33)SRA6version 12.2(33)SRA7version 12.2(33)SRA2version 12.2(33)SRA3version 12.2(33)SRA1version 12.2(33)SRA4version 12.2(33)SRA5version 12.2(28)ZXversion 12.4(4)XCversion 12.4(4)XC1version 12.4(4)XC5version 12.4(4)XC7version 12.4(4)XC3version 12.4(4)XC4version 12.4(4)XC2version 12.4(4)XC6version 12.4(4)XDversion 12.4(4)XD4version 12.4(4)XD10version 12.4(4)XD12version 12.4(4)XD2version 12.4(4)XD8version 12.4(4)XD11version 12.4(4)XD1version 12.4(4)XD5version 12.4(4)XD7version 12.4(4)XD9version 12.4(6)XEversion 12.4(6)XE2version 12.4(6)XE1version 12.3(11)YZ1version 12.3(11)YZversion 12.3(11)YZ2version 12.4(9)XGversion 12.4(9)XG3version 12.4(9)XG5version 12.4(9)XG2version 12.4(9)XG1version 12.4(9)XG4version 12.4(11)XJversion 12.4(11)XJ3version 12.4(11)XJ2version 12.4(11)XJ4version 12.4(6)XTversion 12.4(6)XT1version 12.4(6)XT2version 12.4(6)XPversion 12.2(18)IXAversion 12.2(18)IXBversion 12.2(18)IXB2version 12.2(18)IXB1version 12.2(18)IXCversion 12.2(18)IXDversion 12.2(18)IXD1version 12.2(18)ZUversion 12.2(18)ZU1version 12.2(18)ZU2version 12.2(18)ZYversion 12.2(18)ZY1version 12.2(18)ZY2version 12.4(11)MD2version 12.4(14)XKversion 12.4(11)XVversion 12.4(11)XV1version 12.4(11)XWversion 12.4(11)XW3version 12.4(11)XW7version 12.4(11)XW10version 12.4(11)XW8version 12.4(11)XW9version 12.4(11)XW6version 12.4(11)XW4version 12.4(11)XW1version 12.2(33)SCC5version 12.2(33)SCC4version 12.2(33)SCC3version 12.2(33)SCC1version 12.2(33)SCD5version 12.2(33)SCD1version 12.2(33)SCD7version 12.2(33)SCD4version 12.2(33)SCDversion 12.2(33)SCD6version 12.2(33)SCD3version 12.2(33)SCD2version 12.2(33)SCD8version 15.0(1)M1version 15.0(1)M5version 15.0(1)M4version 15.0(1)M3version 15.0(1)M2version 15.0(1)M6version 15.0(1)Mversion 15.0(1)M7version 15.0(1)M10version 15.0(1)M9version 15.0(1)M8version 15.0(1)XA2version 15.0(1)XA4version 15.0(1)XA1version 15.0(1)XA3version 15.0(1)XAversion 15.0(1)XA5version 15.1(2)Tversion 15.1(1)T4version 15.1(3)T2version 15.1(1)T1version 15.1(2)T0aversion 15.1(3)T3version 15.1(1)T3version 15.1(2)T3version 15.1(2)T4version 15.1(1)T2version 15.1(3)Tversion 15.1(2)T2aversion 15.1(3)T1version 15.1(1)Tversion 15.1(2)T2version 15.1(2)T1version 15.1(2)T5version 15.1(3)T4version 15.1(1)T5version 15.1(1)XBversion 12.2(33)SRE1version 12.2(33)SRE2version 12.2(33)SRE3version 12.2(33)SRE4version 12.2(33)SREversion 12.2(33)SRE0aversion 12.2(33)SRE5version 12.2(33)SRE6version 12.2(33)SRE8version 12.2(33)SRE7version 12.2(33)SRE9version 12.2(33)SRE7aversion 12.2(33)SRE10version 12.2(33)SRE11version 12.2(33)SRE9aversion 12.2(33)SRE12version 12.2(33)SRE13version 12.2(33)SRE14version 12.2(33)SRE15version 15.0(1)XO1version 15.0(1)XOversion 15.0(2)XOversion 15.0(1)S2version 15.0(1)S1version 15.0(1)Sversion 15.0(1)S3aversion 15.0(1)S4version 15.0(1)S5version 15.0(1)S4aversion 12.2(33)IRDversion 12.2(33)IREversion 12.2(33)IRE2version 12.2(33)IRE1version 15.2(1)Sversion 15.2(2)Sversion 15.2(1)S1version 15.2(4)Sversion 15.2(1)S2version 15.2(2)S1version 15.2(2)S2version 15.2(4)S1version 15.2(4)S4version 15.2(4)S6version 15.2(4)S2version 15.2(4)S5version 15.2(4)S3version 15.2(4)S3aversion 15.2(4)S4aversion 15.2(4)S7version 15.3(1)Tversion 15.3(2)Tversion 15.3(1)T1version 15.3(1)T2version 15.3(1)T3version 15.3(1)T4version 15.3(2)T1version 15.3(2)T2version 15.3(2)T3version 15.3(2)T4version 12.4(10b)JDEversion 15.0(1)EYversion 15.0(1)EY1
Vulnerable CVE Program (cve.org) e CISA ADP
Cisco Ios ≥ 15.0 and ≤ 15.6≥ 12.0 and ≤ 12.4 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.8 5.9 nvd@nist.gov via NIST National Vulnerability Database
8.8 CVSS 3.0 High 2.8 5.9 psirt@cisco.com via NIST National Vulnerability Database
8.8 CVSS 3.0 High — — GitHub, Inc. via GitHub Security Advisories
8.8 CVSS 3.0 High — — cisco via CVE Program (cve.org) e CISA ADP
9.0 CVSS 2.0 High 8.0 10.0 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Mar 3, 2022
Federal deadline
Mar 24, 2022
passed 1666 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Exploit-DB

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 70.35%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
  • Hunt retroactively in logs from before Mar 3, 2022 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · cisco/ios, cisco/ios xe
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 13, 2026
  • Affected products added · cisco/ios, intellishield/universal product
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • CVSS changed · 8.8
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2022
  • Added to CISA KEV catalog
    Mar 2, 2022 · CISA
  • 2017
  • CVE published
    Jul 17, 2017 · cisco

Source activity

Repeated readings are counted rather than listed.

  • 3× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

10 on the record

Elsewhere on this site

Cisco
every CVE for this vendor
2022-03
what else CISA listed that month
Memory corruption
same class
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-20301 A vulnerability in the Extensible Messaging Client Protocol (XMCP), also referred to as… Aug 5, 2026
  • CVE-2026-20273 Improper Input Validation in Cisco Ios Xe Aug 5, 2026
  • CVE-2026-20272 Injection in Cisco Ios Xe Aug 5, 2026
  • CVE-2026-20271 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
  • CVE-2026-20269 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026
  • CVE-2026-20270 As part of Cisco's ongoing commitment to proactive security and product quality, the… Aug 5, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2017-6736 is "Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability", rated High. It affects Ios (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 8.8 describes technical severity. EPSS 70.35% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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