CVE Intelligence
Critical Authentication

CVE-2026-20129 — Cisco Catayst SD-WAN Authentication Bypass Vulnerability

A vulnerability in the API user authentication of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to gain access to an affected system as a user who has the netadmin role. The vulnerability is due to improper authentication for requests that are sent to the API. An attacker could exploit this vulnerability by sending a crafted request to the API of an affected system. A successful exploit could allow the attacker to execute commands with the privileges of the netadmin role. Note: Cisco Catalyst SD-WAN Manager releases 20.18 and later are not affected by this vulnerability. 

Published Feb 25, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · 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.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.8% (30-day exploitation probability)+8
  • 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
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.76%
ahead of 54% of scored CVEs · Oct 14, 2026
Affects
Cisco
Catalyst Sd-wan Manager
CVSS base
9.8
Critical · 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
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.

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 Catalyst Sd-wan Manager).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. 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.

VendorProductVersionsStatusSource
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 20.3.4.1.1version 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 20.3.4.3version 20.9.3.1version 20.3.3.2version 20.6.5.2version 20.3.7.1version 20.10.1.1version 20.6.5.2.1version 20.3.4.0.25version 20.6.2.2.4version 20.6.1.2version 20.11.1.1version 20.9.3.0.5version 20.3.4.0.26version 20.6.5.1.3version 20.6.3.0.40version 20.1.3.1version 20.9.2.2version 20.6.5.2.3version 20.6.5.1.4version 20.6.5.3version 20.6.3.0.41version 20.9.3.0.7version 20.6.5.1.5version 20.9.3.0.4version 20.6.4.0.19version 20.6.5.1.6version 20.9.3.0.8version 20.6.3.3version 20.3.7.2version 20.6.5.4version 20.6.5.1.7version 20.9.3.0.12version 20.6.4.2version 20.6.5.5version 20.9.3.2version 20.11.1.2version 20.6.3.4version 20.10.1.2version 20.6.5.1.9version 20.9.3.0.16version 20.6.3.0.45version 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 20.3.3.0.2
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 < 20.18version 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
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
9.8 CVSS 3.1 Critical 3.9 5.9 psirt@cisco.com via NIST National Vulnerability Database
9.8 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:U/C:H/I:H/A:H (score shown at the top: psirt@cisco.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-287 · Improper Authentication

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.76%

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.
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
  • CVSS changed · 9.8
    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
    Feb 25, 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

Elsewhere on this site

Cisco
every CVE for this vendor
Authentication
same class
CWE-287
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-76504 Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability KEV 15d
  • CVE-2026-20262 Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability KEV Jun 15, 2026
  • CVE-2026-20245 Cisco Catalyst SD-WAN Manager Improper Encoding or Escaping of Output Vulnerability KEV Jun 4, 2026
  • CVE-2026-20224 Cisco Catalyst SD-WAN Manager XML External Entity Injection Vulnerability May 14, 2026
  • CVE-2026-20210 Cisco Catalyst SD-WAN Manager Privilege Escalation Vulnerability May 14, 2026
  • CVE-2026-20182 Cisco Catalyst SD-WAN Controller Authentication Bypass Vulnerability KEV 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-2026-20129 is "Cisco Catayst SD-WAN Authentication Bypass Vulnerability", rated Critical. It affects Catalyst Sd-wan Manager (Cisco); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.76% 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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