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CVE Record

CVE-2026-20304: Cisco Catalyst SD-WAN Security Hardening Release - Access Control Vulnerabilities

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20304 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.

CriticalCVSS 9.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Cisco identified critical access-control weaknesses in Catalyst SD-WAN Controller and Manager. A network-connected attacker with limited privileges could potentially cross security boundaries and seriously affect sensitive data, configurations, or service availability. Organizations using any listed release should treat version verification and vendor-directed remediation as urgent.

Executive priority

Assign immediate ownership and require rapid exposure confirmation. Internet-reachable or broadly accessible management systems should receive the highest priority. Accelerate vendor-approved remediation, but preserve operational safeguards because SD-WAN controller changes can affect enterprise-wide connectivity.

Technical view

CVE-2026-20304 groups internally discovered improper-access-control issues under CWE-284. Its CVSS 3.1 score is 9.9: network-accessible, low complexity, low privileges, no user interaction, changed scope, and high confidentiality, integrity, and availability impacts. The supplied evidence does not identify affected interfaces, authorization checks, or individual vulnerability mechanics.

Likely exposure

Potential exposure exists where listed Cisco Catalyst SD-WAN Controller or Manager releases are deployed and reachable by a low-privileged attacker. Actual exposure depends on the exact product role, build, network reachability, and account access. The bundle provides extensive affected-version lists but no CPE mappings or fixed-version table.

Exploitation context

The bundle marks this CVE as absent from KEV and provides no evidence of active exploitation, public proof-of-concept code, or observed attacks. This does not prove exploitation is absent. The low-complexity, network-accessible CVSS assessment makes prompt defensive review appropriate.

Researcher notes

Public details are limited to grouped CWE-284 access-control vulnerabilities and the CVSS vector. The sources do not disclose vulnerable endpoints, authorization paths, indicators of compromise, fixed-version mappings, or separate issue mechanics. Avoid treating the grouped identifier as one fully characterized flaw.

Mitigation direction

  • Review Cisco’s advisory and support guidance for the hardened release applicable to each installed build.
  • Prioritize controlled upgrades after testing controller-manager compatibility, SD-WAN policy behavior, and rollback procedures.
  • Until upgraded, reduce management-plane reachability and privileges through existing Cisco-supported controls.
  • Preserve and review relevant authentication, authorization, and administrative audit logs for suspicious activity.

Validation and detection

  • Inventory all Catalyst SD-WAN Controller and Manager instances, including exact builds and hotfix identifiers.
  • Compare every installed build against the supplied affected versions and Cisco’s current advisory guidance.
  • Confirm management interfaces are not unnecessarily reachable from internet, partner, or untrusted network segments.
  • After remediation, verify installed versions and regression-test authentication, authorization, policy management, and connectivity.
  • Review logs for unexpected privileged actions or configuration changes originating from low-privileged accounts.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-284: Authorization and privilege behavior lookup

Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-20304 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.9 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.9CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H3.16cisco

Vulnerability scoring details

Base CVSS 3.1 score

9.9Critical
CVSS 3.1 vector shape for CVE-2026-20304Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVEADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco Catalyst SD-WAN Controller20.6.4, 20.9.2, 20.3.6, 20.7.2, 20.7.1, 20.5.1, 20.6.2, 19.3.0, 20.6.1, 17.2.4, 18.2.0, 18.4.6, 19.1.0, 19.2.4, 19.2.929, 18.3.8, 18.4.303, 18.3.7, 18.4.1, 19.2.097, 19.2.0, 19.2.099, 18.3.6, 20.4.2, 19.0.0, 20.9.1, 20.3.5, 20.3.1, 18.3.5, 20.6.3, 18.4.3, 18.4.4, 18.3.3, 17.2.8, 20.8.1, 19.2.32, 19.2.2, 17.2.5, 18.4.0, 20.4.1.1, 20.1.3, 20.1.2, 17.2.10, 19.2.098, 20.1.1, 17.2.6, 19.2.1, 18.3.4, 20.4.1, 17.2.9, 19.2.31, 19.0.1a, 18.3.0, 17.2.7, 18.4.5, 20.3.4, 20.3.3, 20.4.1.2, 20.3.2, 18.3.1, 20.1.12, 19.2.3, 20.10.1, 20.6.5, 20.3.7, 20.9.3, 20.11.1, 20.6.3.2, 20.4.2.3, 20.3.5.1, 20.3.4.3, 20.9.3.1, 20.6.4.1, 20.3.3.2, 20.6.5.2, 20.3.7.1, 20.11.1.1, 20.10.1.1, 20.6.1.2, 20.1.3.1, 20.9.2.2, 20.6.5.3, 20.6.3.3, 20.3.7.2, 20.6.5.4, 20.9.2.3, 20.9.4, 20.12.1, 20.3.8, 20.6.6, 20.12.2, 20.13.1, 20.9.5, 20.12.3, 20.6.7, 20.9.5.1, 20.14.1, 20.12.3.1, 20.12.4, 20.15.1, 20.9.6, 20.6.8, 20.16.1, 20.9.5.3, 20.12.4.1, 20.15.2, 20.12.5, 20.9.7, 20.15.3, 20.12.5.1, 20.12.5.2, 20.15.4, 20.9.7.1, 20.18.1, 20.12.6, 20.9.8, 20.15.4.1, 20.18.2, 26.1.1, 20.15.4.2, 20.18.2.1, 20.12.5.3, 20.12.6.1, 20.9.8.2, 20.15.5, 20.18.3, 20.12.7, 20.9.9, 20.18.2.2, 20.12.5.4, 20.12.7.1, 20.15.5.1, 20.15.4.3, 20.12.6.2, 20.15.5.2, 20.15.4.4, 26.1.1.1, 20.9.9.1, 20.18.3.1, 26.1.1.2, 20.15.4.5, 20.15.5.3, 20.12.7.2, 20.9.9.2, 20.18.4, 20.15.6, 20.12.8unknown
CiscoCisco Catalyst SD-WAN Manager20.1.12, 19.2.1, 18.4.4, 18.4.5, 20.1.1.1, 20.1.1, 19.3.0, 19.2.2, 19.2.099, 18.3.6, 18.3.7, 19.2.0, 18.3.8, 19.0.0, 19.1.0, 18.4.302, 18.4.303, 19.2.097, 19.2.098, 17.2.10, 18.3.6.1, 19.0.1a, 18.2.0, 18.4.3, 18.4.1, 17.2.8, 18.3.3.1, 18.4.0, 18.3.1, 17.2.6, 17.2.9, 18.3.4, 17.2.5, 18.3.1.1, 18.3.5, 18.4.0.1, 18.3.3, 17.2.7, 17.2.4, 18.3.0, 19.2.3, 18.4.501_ES, 20.3.1, 20.1.2, 19.2.929, 19.2.31, 20.3.2, 19.2.32, 20.3.2_925, 20.3.2.1, 20.3.2.1_927, 18.4.6, 20.1.2_937, 20.4.1, 20.3.2_928, 20.3.2_929, 20.4.1.0.1, 20.3.2.1_930, 19.2.4, 20.5.0.1.1, 20.4.1.1, 20.3.3, 19.2.4.0.1, 20.3.2_937, 20.3.3.1, 20.5.1, 20.1.3, 20.3.3.0.4, 20.3.3.1.2, 20.3.3.1.1, 20.4.1.2, 20.3.3.0.2, 20.4.1.1.5, 20.4.1.0.01, 20.4.1.0.02, 20.3.3.1.7, 20.3.3.1.5, 20.5.1.0.1, 20.3.3.1.10, 20.3.3.0.8, 20.4.2, 20.4.2.0.1, 20.3.4, 20.3.3.0.14, 19.2.4.0.8, 19.2.4.0.9, 20.3.4.0.1, 20.3.2.0.5, 20.6.1, 20.5.1.0.2, 20.3.3.0.17, 20.6.1.1, 20.6.0.18.3, 20.3.2.0.6, 20.6.0.18.4, 20.4.2.0.2, 20.3.3.0.16, 20.3.4.0.5, 20.6.1.0.1, 20.3.4.0.6, 20.6.2, 20.7.1EFT2, 20.3.4.0.9, 20.3.4.0.11, 20.4.2.0.4, 20.3.3.0.18, 20.7.1, 20.6.2.1, 20.3.4.1, 20.5.1.1, 20.4.2.1, 20.4.2.1.1, 20.3.4.1.1, 20.3.813, 20.3.4.0.19, 20.4.2.2.1, 20.5.1.2, 20.3.4.2, 20.3.814, 20.4.2.2, 20.6.2.2, 20.3.4.2.1, 20.7.1.1, 20.3.4.1.2, 20.6.2.2.2, 20.3.4.0.20, 20.6.2.2.3, 20.4.2.2.2, 20.3.5, 20.6.2.0.4, 20.4.2.2.3, 20.3.4.0.24, 20.6.2.2.7, 20.6.3, 20.3.4.2.2, 20.4.2.2.4, 20.7.1.0.2, 20.8.1, 20.3.5.0.8, 20.3.5.0.9, 20.4.2.2.8, 20.3.5.0.7, 20.6.3.0.7, 20.6.3.0.5, 20.6.3.0.10, 20.6.3.0.2, 20.7.2, 20.9.1EFT2, 20.6.3.0.11, 20.6.3.1, 20.6.3.0.14, 20.6.4, 20.9.1, 20.6.3.0.19, 20.6.3.0.18, 20.3.6, 20.9.1.1, 20.6.3.0.23, 20.6.4.0.4, 20.6.3.0.25, 20.6.5, 20.6.3.0.27, 20.9.2, 20.9.2.1, 20.6.3.0.29, 20.6.3.0.31, 20.6.3.0.32, 20.10.1, 20.6.3.0.33, 20.9.2.0.01, 20.9.1_LI_Images, 20.10.1_LI_Images, 20.9.2_LI_Images, 20.3.7, 20.9.3, 20.6.5.1, 20.11.1, 20.11.1_LI_Images, 20.9.3_LI_ Images, 20.6.3.1.1, 20.9.3.0.2, 20.6.5.1.2, 20.9.3.0.3, 20.4.2.3, 20.6.3.2, 20.6.4.1, 20.6.3.0.38, 20.6.3.0.39, 20.3.5.1, 20.3.4.3, 20.9.3.1, 20.3.3.2, 20.6.5.2, 20.3.7.1, 20.10.1.1, 20.6.5.2.1, 20.3.4.0.25, 20.6.2.2.4, 20.6.1.2, 20.11.1.1, 20.9.3.0.5, 20.3.4.0.26, 20.6.5.1.3, 20.6.3.0.40, 20.1.3.1, 20.9.2.2, 20.6.5.2.3, 20.6.5.1.4, 20.6.5.3, 20.6.3.0.41, 20.9.3.0.7, 20.6.5.1.5, 20.9.3.0.4, 20.6.4.0.19, 20.6.5.1.6, 20.9.3.0.8, 20.6.3.3, 20.3.7.2, 20.6.5.4, 20.6.5.1.7, 20.9.3.0.12, 20.6.4.2, 20.6.5.5, 20.9.3.2, 20.11.1.2, 20.6.3.4, 20.10.1.2, 20.6.5.1.9, 20.9.3.0.16, 20.6.3.0.45, 20.6.5.1.10, 20.9.3.0.17, 20.6.5.2.4, 20.6.4.0.21, 20.9.3.0.18, 20.6.3.0.46, 20.6.3.0.47, 20.9.2.3, 20.9.3.2_LI_Images, 20.9.3.0.21, 20.9.3.0.20, 20.9.4_LI_Images, 20.9.4, 20.6.5.1.11, 20.12.1, 20.12.1_LI_Images, 20.6.5.1.13, 20.9.3.0.23, 20.6.5.2.8, 20.9.4.1, 20.9.4.1_LI_Images, 20.9.3.0.25, 20.9.3.0.24, 20.6.5.1.14, 20.3.8, 20.6.6, 20.9.3.0.26, 20.6.3.0.51, 20.9.3.0.29, 20.12.2, 20.12.2_LI_Images, 20.6.6.0.1, 20.13.1_LI_Images, 20.9.4.0.4, 20.13.1, 20.9.4.1.1, 20.9.5, 20.9.5_LI_Images, 20.12.3_LI_Images, 20.12.3, 20.9.4.1.3, 20.6.7, 20.9.5.1, 20.9.5.1_LI_Images, 20.9.4.1.6, 20.14.1, 20.14.1_LI_Images, 20.9.5.2, 20.9.5.2.1, 20.9.5.2_LI_Images, 20.12.3.1, 20.12.4, 20.15.1_LI_Images, 20.15.1, 20.9.5.1.4, 20.9.5.2.7, 20.9.5.2.13, 20.9.6, 20.9.6_LI_Images, 20.9.5.2.14, 20.6.8, 20.12.4.0.03, 20.16.1, 20.16.1_LI_Images, 20.12.4_LI_Images, 20.9.5.2.16, 20.12.4.0.4, 20.12.401, 20.9.5.3, 20.9.5.3_LI_Images, 20.12.4.1_LI_Images, 20.12.4.1, 20.9.5.2.21, 20.9.6.0.3, 20.12.4.0.6, 20.15.2_LI_Images, 20.15.2, 20.12.4_Monthly_ES5, 20.12.5, 20.12.5_LI_Images, 20.9.7_LI _Images, 20.9.7, 20.15.3, 20.15.3_ LI _Images, 20.12.501, 20.12.5.1_LI_Images, 20.12.5.1, 20.12.5.2_LI_Images, 20.12.5.2, 20.15.3.1, 20.15.4_LI_Images, 20.15.4, 20.9.7.1_LI _Images, 20.9.7.1, 20.18.1, 20.18.1_LI_Images, 20.12.6_LI_Images, 20.12.6, 20.12.5.1.01, 26.0.1, 20.9.8, 20.9.8_LI_Images, 20.18.2, 20.15.4.1_LI_Images, 20.15.4.1, 20.18.2_LI_Images, 26.1.1, 26.1.1_LI_Images, 20.18.2.1_LI_Images, 20.18.2.1, 20.15.4.2_LI_Images, 20.15.4.2, 20.12.6.1, 20.12.6.1_LI_Images, 20.12.5.3, 20.12.5.3_LI_Images, 20.9.8.2_LI_Images, 20.9.8.2, 20.18.3, 20.18.3_LI_Images, 20.15.5, 20.15.5_LI_Images, 20.12.7, 20.12.7_LI_Images, 20.9.9, 20.9.9_LI_Images, 20.18.2.2, 20.18.2.2_LI_Images, 20.12.5.4, 20.12.5.4_LI_ Images, 20.12.7.1_LI_Images, 20.12.6.2_LI_Images, 20.12.7.1, 20.15.5.1, 20.15.4.3, 20.15.4.3_LI_Images, 20.15.5.1_LI_Images, 20.12.6.2, 20.15.5.2, 20.15.5.2_LI_Images, 26.1.1.1_LI_Images, 20.15.4.4, 20.15.4.4_LI_Images, 26.1.1.1, 20.9.9.1_LI_Images, 20.9.9.1, 20.18.3.1_LI_Images, 20.18.3.1, 26.1.1.2, 26.1.1.2_LI_Images, 20.15.4.5, 20.15.4.5_LI_Images, 20.15.5.3, 20.15.5.3_LI_Images, 20.12.7.2_LI_Images, 20.12.7.2, 20.9.9.2, 20.9.9.2_LI_Images, 20.15.6, 20.15.6_LI_Images, 20.18.4, 20.12.8, 20.12.8_LI_Imagesunknown
Weakness

CWE details

CWE-284

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-284 · source CWE mapping

Improper Access Control

Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs