CISA KEV Critical Authentication

CVE-2026-20127 — Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability

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 an 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 Feb 25, 2026 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: cisco

Urgent

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 · Feb 25, 2026 Metasploit modules · 1 Proofs of concept on GitHub · 9

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (metasploit, github)+18
EPSS 88.5% (30-day exploitation probability)+15
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

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 Feb 25, 2026

EPSS FIRST

88.48%

ahead of 100% of scored CVEs · Oct 14, 2026

Affects

Cisco

Catalyst Sd-wan Manager

CVSS base

10.0

Critical · 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

Yes

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

Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines 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.

US federal deadline: Feb 27, 2026 — passed 230 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.

Identify exposed assets running the affected vendor/product/version combinations (Cisco Catalyst Sd-wan Manager).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cisco	Catalyst Sd-wan Manager	version 20.6.5.1.10version 20.9.3.0.17version 20.6.5.2.4version 20.6.4.0.21version 20.9.3.0.18version 20.6.3.0.46version 20.6.3.0.47version 20.9.2.3 and 287 more version 20.9.3.2_LI_Imagesversion 20.9.3.0.21version 20.9.3.0.20version 20.9.4_LI_Imagesversion 20.9.4version 20.6.5.1.11version 20.12.1version 20.12.1_LI_Imagesversion 20.6.5.1.13version 20.9.3.0.23version 20.6.5.2.8version 20.9.4.1version 20.9.4.1_LI_Imagesversion 20.9.3.0.25version 20.9.3.0.24version 20.6.5.1.14version 20.3.8version 20.6.6version 20.9.3.0.26version 20.6.3.0.51version 20.9.3.0.29version 20.12.2version 20.12.2_LI_Imagesversion 20.6.6.0.1version 20.13.1_LI_Imagesversion 20.9.4.0.4version 20.13.1version 20.9.4.1.1version 20.9.5version 20.9.5_LI_Imagesversion 20.12.3_LI_Imagesversion 20.12.3version 20.9.4.1.3version 20.6.7version 20.9.5.1version 20.9.5.1_LI_Imagesversion 20.9.4.1.6version 20.14.1version 20.14.1_LI_Imagesversion 20.9.5.2version 20.9.5.2.1version 20.9.5.2_LI_Imagesversion 20.12.3.1version 20.12.4version 20.15.1_LI_Imagesversion 20.15.1version 20.9.5.1.4version 20.9.5.2.7version 20.9.5.2.13version 20.9.6version 20.9.6_LI_Imagesversion 20.9.5.2.14version 20.6.8version 20.12.4.0.03version 20.16.1version 20.16.1_LI_Imagesversion 20.12.4_LI_Imagesversion 20.9.5.2.16version 20.12.4.0.4version 20.12.401version 20.9.5.3version 20.9.5.3_LI_Imagesversion 20.12.4.1_LI_Imagesversion 20.12.4.1version 20.9.5.2.21version 20.9.6.0.3version 20.12.4.0.6version 20.15.2_LI_Imagesversion 20.15.2version 20.12.4_Monthly_ES5version 20.12.5version 20.12.5_LI_Imagesversion 20.9.7_LI _Imagesversion 20.9.7version 20.15.3version 20.15.3_ LI _Imagesversion 20.12.501version 20.12.5.1_LI_Imagesversion 20.12.5.1version 20.12.5.2_LI_Imagesversion 20.12.5.2version 20.15.3.1version 20.15.4_LI_Imagesversion 20.15.4version 20.9.7.1_LI _Imagesversion 20.9.7.1version 20.18.1version 20.18.1_LI_Imagesversion 20.12.6_LI_Imagesversion 20.12.6version 20.12.5.1.01version 20.9.8version 20.9.8_LI_Imagesversion 20.18.2version 20.15.4.1_LI_Imagesversion 20.15.4.1version 20.18.2_LI_Imagesversion 20.1.12version 19.2.1version 18.4.4version 18.4.5version 20.1.1.1version 20.1.1version 19.3.0version 19.2.2version 19.2.099version 18.3.6version 18.3.7version 19.2.0version 18.3.8version 19.0.0version 19.1.0version 18.4.302version 18.4.303version 19.2.097version 19.2.098version 17.2.10version 18.3.6.1version 19.0.1aversion 18.2.0version 18.4.3version 18.4.1version 17.2.8version 18.3.3.1version 18.4.0version 18.3.1version 17.2.6version 17.2.9version 18.3.4version 17.2.5version 18.3.1.1version 18.3.5version 18.4.0.1version 18.3.3version 17.2.7version 17.2.4version 18.3.0version 19.2.3version 18.4.501_ESversion 20.3.1version 20.1.2version 19.2.929version 19.2.31version 20.3.2version 19.2.32version 20.3.2_925version 20.3.2.1version 20.3.2.1_927version 18.4.6version 20.1.2_937version 20.4.1version 20.3.2_928version 20.3.2_929version 20.4.1.0.1version 20.3.2.1_930version 19.2.4version 20.5.0.1.1version 20.4.1.1version 20.3.3version 19.2.4.0.1version 20.3.2_937version 20.3.3.1version 20.5.1version 20.1.3version 20.3.3.0.4version 20.3.3.1.2version 20.3.3.1.1version 20.4.1.2version 20.3.3.0.2version 20.4.1.1.5version 20.4.1.0.01version 20.4.1.0.02version 20.3.3.1.7version 20.3.3.1.5version 20.5.1.0.1version 20.3.3.1.10version 20.3.3.0.8version 20.4.2version 20.4.2.0.1version 20.3.4version 20.3.3.0.14version 19.2.4.0.8version 19.2.4.0.9version 20.3.4.0.1version 20.3.2.0.5version 20.6.1version 20.5.1.0.2version 20.3.3.0.17version 20.6.1.1version 20.6.0.18.3version 20.3.2.0.6version 20.6.0.18.4version 20.4.2.0.2version 20.3.3.0.16version 20.3.4.0.5version 20.6.1.0.1version 20.3.4.0.6version 20.6.2version 20.7.1EFT2version 20.3.4.0.9version 20.3.4.0.11version 20.4.2.0.4version 20.3.3.0.18version 20.7.1version 20.6.2.1version 20.3.4.1version 20.5.1.1version 20.4.2.1version 20.4.2.1.1version 20.3.4.1.1version 20.3.813version 20.3.4.0.19version 20.4.2.2.1version 20.5.1.2version 20.3.4.2version 20.3.814version 20.4.2.2version 20.6.2.2version 20.3.4.2.1version 20.7.1.1version 20.3.4.1.2version 20.6.2.2.2version 20.3.4.0.20version 20.6.2.2.3version 20.4.2.2.2version 20.3.5version 20.6.2.0.4version 20.4.2.2.3version 20.3.4.0.24version 20.6.2.2.7version 20.6.3version 20.3.4.2.2version 20.4.2.2.4version 20.7.1.0.2version 20.8.1version 20.3.5.0.8version 20.3.5.0.9version 20.4.2.2.8version 20.3.5.0.7version 20.6.3.0.7version 20.6.3.0.5version 20.6.3.0.10version 20.6.3.0.2version 20.7.2version 20.9.1EFT2version 20.6.3.0.11version 20.6.3.1version 20.6.3.0.14version 20.6.4version 20.9.1version 20.6.3.0.19version 20.6.3.0.18version 20.3.6version 20.9.1.1version 20.6.3.0.23version 20.6.4.0.4version 20.6.3.0.25version 20.6.5version 20.6.3.0.27version 20.9.2version 20.9.2.1version 20.6.3.0.29version 20.6.3.0.31version 20.6.3.0.32version 20.10.1version 20.6.3.0.33version 20.9.2.0.01version 20.9.1_LI_Imagesversion 20.10.1_LI_Imagesversion 20.9.2_LI_Imagesversion 20.3.7version 20.9.3version 20.6.5.1version 20.11.1version 20.11.1_LI_Imagesversion 20.9.3_LI_ Imagesversion 20.6.3.1.1version 20.9.3.0.2version 20.6.5.1.2version 20.9.3.0.3version 20.4.2.3version 20.6.3.2version 20.6.4.1version 20.6.3.0.38version 20.6.3.0.39version 20.3.5.1version 20.3.4.3	Vulnerable	CVE Program (cve.org) e CISA ADP
Cisco	Catalyst Sd-wan Manager	< 20.9.8.2≥ 20.11 and < 20.12.5.3≥ 20.13 and < 20.15.4.2≥ 20.16 and < 20.18.2.1version 20.12.6	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

None

User interaction

None

Scope

Changed

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.

Score	Version	Severity	Expl.	Impact	Scored by
10.0	CVSS 3.1	Critical	3.9	6.0	psirt@cisco.com via NIST National Vulnerability Database
10.0	CVSS 3.1	Critical	3.9	6.0	nvd@nist.gov via NIST National Vulnerability Database
10.0	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
10.0	CVSS 3.1	Critical	—	—	cisco via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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-287 · Improper Authentication

Other CVEs with this weakness →

CISA KEV details CISA

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

Listed

Feb 25, 2026

Federal deadline

Feb 27, 2026

passed 230 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.

Metasploit modules

Cisco Catalyst SD-WAN Controller Authentication Bypass normal Feb 25, 2026

Proofs of concept on GitHub

zerozenxlabs/CVE-2026-20127---Cisco-SD-WAN-Preauth-RCE ★ 29 Mar 4, 2026
An exploit for the Cisco Catalyst SD-WAN Controller authentication bypass vulnerability, CVE-2026-20127 ★ 24 Mar 9, 2026
Cisco Catalyst SD-WAN 身份验证绕过漏洞(CVE-2026-20127)利用EXP ★ 4 Mar 5, 2026
yonathanpy/CVE-2026-20127-Cisco-SD-WAN-Preauth-RCE ★ 2 Mar 7, 2026
gigachadusers/cve-2026-20127 ★ 2 Apr 15, 2026
Walkthrough of the CVSS 10.0 authentication bypass in Cisco Catalyst SD-WAN from first malformed peering request to root on the management plane. ★ 0 Mar 4, 2026
Cisco SD-WAN Exposure & Potential Vulnerability Scanner (Passive Fingerprinting) 2026 ★ 0 Mar 8, 2026
CVE-2026-20127 ★ 0 Jun 14, 2026
anuththara2007-W/CVE-2026-20127-Exploit-Extension ★ 0 Jul 12, 2026

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 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 88.48%

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).
Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Hunt retroactively in logs from before Feb 25, 2026 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · cisco/cisco catalyst sd-wan manager
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
Affected products added · cisco/catalyst sd-wan manager, cisco/sd-wan vbond orchestrator, cisco/sd-wan vsmart controller
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 10.0
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
CVE published
Feb 25, 2026 · cisco
Added to CISA KEV catalog
Feb 24, 2026 · CISA

Source activity

Repeated readings are counted rather than listed.

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

References

4 on the record

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHch
Vendor Advisory, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
github.com/advisories/GHSA-p4cq-46q3-jr7w
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2026-20127
GitHub Security Advisories

Elsewhere on this site

Cisco
every CVE for this vendor

2026-02
what else CISA listed that month

Authentication
same class

CWE-287
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-76504 Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability KEV 15d
Medium CVE-2026-20262 Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability KEV Jun 15, 2026
High CVE-2026-20245 Cisco Catalyst SD-WAN Manager Improper Encoding or Escaping of Output Vulnerability KEV Jun 4, 2026
High CVE-2026-20224 Cisco Catalyst SD-WAN Manager XML External Entity Injection Vulnerability May 14, 2026
Medium CVE-2026-20210 Cisco Catalyst SD-WAN Manager Privilege Escalation Vulnerability May 14, 2026
Medium CVE-2026-20209 Cisco Catalyst SD-WAN Manager Privilege Escalation Vulnerability May 14, 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-2026-20127 is "Cisco Catalyst SD-WAN Controller and Manager Authentication Bypass Vulnerability", rated Critical. It affects Catalyst Sd-wan Manager (Cisco); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 10.0 describes technical severity. EPSS 88.48% 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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