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CVE-2026-20310: Improper Link Resolution Before File Access ('Link Following') in Cisco Cisco Catalyst SD-WAN Controller

0
Critical
VulnerabilityCVE-2026-20310cvecve-2026-20310gcveosvghsa-fhhx-46fx-737rghsaghsa-pqwq-qr78-m9wccve-2026-20304
Published: 08/05/2026 (08/05/2026, 16:30:27 UTC)
Source: CVE Database V5
Vendor/Project: Cisco
Product: Cisco Catalyst SD-WAN Controller

Description

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.

CVSS v3.1

Score 9.1critical

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected software

Cisco

Cisco Catalyst SD-WAN Controller

Affected versions
=20.6.4=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

Cisco

Cisco Catalyst SD-WAN Manager

Affected versions
=20.1.12=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=20.6.3.1.1=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=20.15.3=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=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=20.12.7.1_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_Images

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 08/15/2026, 13:18:27 UTC

Technical Analysis

Cisco Catalyst SD-WAN Controller contains a vulnerability identified as CVE-2026-20310, which involves improper link resolution before file access (CWE-59). This flaw could allow an attacker with high privileges to exploit the system by manipulating symbolic links or similar mechanisms before file access occurs. The vulnerability was found during an internal security review by Cisco and affects a wide range of specific software versions. The CVSS v3.1 base score is 9.1, reflecting critical impact on confidentiality, integrity, and availability with network attack vector and no user interaction required. No vendor advisory or patch information is currently provided, and no known exploits in the wild have been reported.

Potential Impact

The vulnerability allows an attacker with high privileges to potentially manipulate file access through improper link resolution, leading to full compromise of confidentiality, integrity, and availability of the affected system. Given the CVSS score of 9.1, the impact is critical, potentially enabling remote exploitation without user interaction but requiring high privileges.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Cisco has released software hardening updates addressing multiple vulnerabilities including this one, but no specific patch or remediation level is currently documented. Users should monitor Cisco advisories for updates and apply patches once available.

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Technical Details

Data Version
5.2
Assigner Short Name
cisco
Date Reserved
2025-10-08T11:59:15.409Z
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6a736b62bf8831d5392da51b

Added to database: 08/05/2026, 16:57:06 UTC

Last enriched: 08/15/2026, 13:18:27 UTC

Last updated: 09/18/2026, 10:33:01 UTC

Views: 70

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