What is CVE-2026-20182?

CVE-2026-20182 is Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability. The supplied enrichment data classifies it as Auth Bypass mapped to CWE-287 Improper Authentication.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

20 public PoC repositories reported; 1 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, identity provider logs, authentication audit logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-20182 using CVSS 10, EPSS 90%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVcriticalAuth Bypasspublic exploit

CVE-2026-20182

Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2026-20182 in CISA KEV with required action: Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlined in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and fixed after the was disclosed in February 2026. This new advisory is for a new vulnerability in the control connection handshaking. The section of this advisory includes Show Control Connections guidance to help with system checks. A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to the affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.

Published May 14, 2026Updated Jun 17, 2026Sources: NVD, Cisco (CNA), CISA, FIRST EPSS, GitHub, GitHub Security Advisory

Triage

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

Exploitation

Confirmed

CISA KEV, listed May 14, 2026

EPSS

90%

ahead of 99.8% of scored CVEs

Affects

Cisco

163 products listed

CVSS base

critical

CISA SSVC assessment

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

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Cisco Catalyst SD-WAN Controller to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlined in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

Federal deadline May 17, 2026 — passed 98 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Cisco	Cisco Catalyst SD-WAN Controller	20.6.4	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.9.2	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.3.6	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.7.2	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.7.1	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.5.1	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.6.2	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	19.3.0	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	20.6.1	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	17.2.4	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	18.2.0	Vulnerable
Cisco	Cisco Catalyst SD-WAN Controller	18.4.6	Vulnerable

Attack characteristics

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

Availability

High

Confidentiality

High

Integrity

High

Scope

Changed

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Source
10	CVSS 3.1	critical	3.9	6	Cisco (CNA), GHSA

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weakness & attack patterns

CWE-287Improper Authentication

Inferred from the weakness class — not observed against this CVE.

CAPEC-115 · Authentication BypassCAPEC-94 · Adversary in the Middle

T1548Abuse Elevation Control Mechanism
T1040Network Sniffing
T1185Browser Session Hijacking

CISA KEV details

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

CISAThat month →

Listed

May 14, 2026

Federal deadline

May 17, 2026

passed 98 days 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 date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

1 of the 5 sampled are weaponized

Detection

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

Prioritize edge telemetry for network-reachable Cisco Catalyst SD-WAN Controller, Cisco Catalyst SD-WAN Manager.
Monitor for scanner or exploit-pattern traffic after 20 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSidentity provider logsauthentication audit logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 10.0 (AV:N)
Jun 17, 2026 · NVD
Added to CISA KEV catalog
May 14, 2026 · CISA
Initial · CVE published
May 14, 2026 · NVD
Added · GHSA-p83j-mxpw-gqpj published (critical)
May 14, 2026 · GitHub Security Advisory

References

7 on the record

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk
Not Applicable
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa2-v69WY2SW
Vendor Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20182
US Government Resource
nvd.nist.gov/vuln/detail/CVE-2026-20182
NVD, Vendor Advisory
github.com/advisories/GHSA-p83j-mxpw-gqpj
Exploit, Third Party Advisory
www.cisa.gov/news-events/directives/ed-26-03-mitigate-vulnerabilities-cisco-sd-wan-systems
US Government Resource
www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems
US Government Resource

Elsewhere on this site

Ciscoevery CVE for this vendor
May 2026what else CISA listed
Auth Bypasssame class
CWE-287other pages naming this weakness

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 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 record1

What should defenders know first?

CVE-2026-20182 is Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability, a critical vulnerability affecting Cisco Catalyst SD-WAN Controller, Cisco Catalyst SD-WAN Manager from Cisco. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 20 public PoC repositories reported; 1 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 10 describes technical severity, while EPSS 90% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.