High Access control

CVE-2026-20167 — Cisco IoT Field Network Director Remote Device Denial of Service Vulnerability

A vulnerability in the web-based management interface of Cisco IoT Field Network Director could allow an authenticated, remote attacker with low privileges to cause a DoS condition on a remotely managed router. This vulnerability is due to improper error handling. An attacker could exploit this vulnerability by submitting crafted input to the web-based management interface. A successful exploit could allow the attacker to request unauthorized files from a remote router, causing the router to reload and resulting in a DoS condition.

Published May 6, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: cisco

Low

Who exploits it and how urgent it is

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

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
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

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.27%

ahead of 18% of scored CVEs · Oct 14, 2026

Affects

Cisco

Cisco IoT Field Network Director (IoT-FND) and 1 more

CVSS base

7.7

High · 2 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

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

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.

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.

Identify exposed assets running the affected vendor/product/version combinations (Cisco Cisco IoT Field Network Director (IoT-FND), Cisco Iot Field Network Director).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cisco	Cisco IoT Field Network Director (IoT-FND)	version 4.4.1version 4.12.1version 4.12.0version 4.11.0version 4.9.2version 4.10.0version 4.9.1version 4.9.0 and 22 more version 4.8.1version 4.8.0version 4.7.2version 4.7.1version 4.6.2version 4.7.0version 4.3.1version 4.5.0version 4.1.2version 4.3.2version 4.4.4version 4.6.0version 4.3.0version 4.4.2version 4.2.0version 4.4.0version 4.1.1version 4.6.1version 4.1.3version 4.1.0version 4.4.3version 4.5.1	Vulnerable	CVE Program (cve.org) e CISA ADP
Cisco	Iot Field Network Director	< 5.0.0-117	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

Changed

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Scored by
7.7	CVSS 3.1	High	3.1	4.0	psirt@cisco.com via NIST National Vulnerability Database
7.7	CVSS 3.1	High	—	—	cisco via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H (score shown at the top: psirt@cisco.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-284 · Improper Access Control

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.27%

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).
Audit administrative actions and access to resources outside each user’s normal pattern.

web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · cisco/cisco iot field network director (iot-fnd)
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.7
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
May 6, 2026 · cisco

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iot-fnd-dos-n8
Vendor Advisory, NIST National Vulnerability Database

Elsewhere on this site

Cisco
every CVE for this vendor

Access control
same class

CWE-284
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-20168 Cisco IoT Field Network Director Path Traversal Vulnerability May 6, 2026
Medium CVE-2026-20169 Cisco IoT Field Network Director Command Injection Vulnerability May 6, 2026
High CVE-2023-44487 HTTP/2 Rapid Reset Attack Vulnerability KEV Oct 10, 2023

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-2026-20167 is "Cisco IoT Field Network Director Remote Device Denial of Service Vulnerability", rated High. It affects Cisco IoT Field Network Director (IoT-FND) (Cisco); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.7 describes technical severity. EPSS 0.27% 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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