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CVE Record

CVE-2026-20310: Cisco SD-WAN Software Security Hardening Release - Improper Link Resolution Before File Access

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 software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20310 are related to improper link resolution before file access issues that are grouped under the Common Weakness Enumeration (CWE) CWE-59.

CriticalCVSS 9.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Cisco Catalyst SD-WAN Controller and Manager contain a file-access weakness involving improperly resolved links. An attacker with high privileges and network access could potentially cross a security boundary and seriously affect confidentiality, integrity, and availability. The supplied evidence does not establish active exploitation.

Executive priority

Prioritize immediate inventory and Cisco-guided remediation planning. High privileges are required, so this is not evidence of unauthenticated compromise; however, successful exploitation could cross security boundaries and materially disrupt SD-WAN management. Escalate deployments with weak administrative controls, broad management exposure, or suspected privileged-account compromise.

Technical view

CVE-2026-20310 is classified as CWE-59, improper link resolution before file access. Its CVSS 3.1 score is 9.1 (AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H), indicating network reachability, low complexity, required high privileges, no user interaction, changed scope, and potentially high impact across all three security objectives.

Likely exposure

Exposure is limited to organizations operating the enumerated Cisco Catalyst SD-WAN Controller or Manager versions. Because the record supplies no CPE mappings and marks default version status unknown, teams should verify exact product roles, versions, deployment reachability, and Cisco advisory status rather than relying on broad version assumptions.

Exploitation context

The supplied bundle reports no CISA KEV listing and provides no evidence of exploitation in the wild or a public proof of concept. Exploitation requires high privileges, which reduces initial-access likelihood, but network reachability, low complexity, changed scope, and high potential impact make privileged-account compromise especially consequential.

Researcher notes

The public bundle identifies CWE-59 but does not describe the vulnerable file operation, link type, reachable path, exploitation primitive, detection indicators, workarounds, or specific fixed releases. Consequently, exposure and remediation conclusions should remain tied to Cisco's advisory. No exploit development or weaponization claims are supported.

Mitigation direction

  • Review Cisco's advisory for current fixed-release and upgrade guidance.
  • Upgrade affected Controller and Manager deployments through an approved change process.
  • Restrict management-plane access to authorized administrative networks and identities.
  • Strengthen privileged-account controls, including multifactor authentication and access review.

Validation and detection

  • Inventory all Catalyst SD-WAN Controller and Manager instances and exact versions.
  • Compare each version directly with Cisco's current advisory guidance.
  • Verify management interfaces are inaccessible from untrusted networks.
  • Review privileged access and relevant file-access activity for unexplained changes.
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 · low confidence lookup

CWE-59: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-20310 mapping review

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

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/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
9.1CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H2.36cisco

Vulnerability scoring details

Base CVSS 3.1 score

9.1Critical
CVSS 3.1 vector shape for CVE-2026-20310Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/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, 20.9.9.2unknown
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, 20.12.8_LI_Imagesunknown
Weakness

CWE details

CWE-59

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

CWE-59 · source CWE mapping

Improper Link Resolution Before File Access ('Link Following')

Improper Link Resolution Before File Access ('Link Following') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs