# CVE-2026-20310 — Cisco Catalyst SD-WAN Controller

> As of 2026-08-14, CVE-2026-20310 is a CRITICAL-severity vulnerability in Cisco Catalyst SD-WAN Controller, CVSS v3.1 9.1, EPSS 0.5% (46.4th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-20310, most recently “Multiple Critical Vulnerabilities in Cisco Catalyst SD-WAN Software (CVE-2026-20303, CVE-2026-20304, CVE-2026-20310, CVE-2026-20312, CVE-2026-20313)”.

**Last updated:** 2026-08-14

## What is CVE-2026-20310?

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.

The record classifies CVE-2026-20310 under weakness class [CWE-59](https://intel.threadlinqs.com/cwe/CWE-59). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 66 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.1 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.5% probability of exploitation in the next 30 days, higher than 46.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-05, last modified 2026-08-14

## Is CVE-2026-20310 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Cisco](https://intel.threadlinqs.com/vendors/cisco): Catalyst SD-WAN Controller, Catalyst SD-WAN Manager

## How to fix CVE-2026-20310

No vendor patch reference has been recorded for CVE-2026-20310 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-20310

1 tracked threat in the Threadlinqs corpus references CVE-2026-20310, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Critical Vulnerabilities in Cisco Catalyst SD-WAN Software (CVE-2026-20303, CVE-2026-20304, CVE-2026-20310, CVE-2026-20312, CVE-2026-20313)](https://intel.threadlinqs.com/threat/TL-2026-1905) — CRITICAL · 2026-08-06

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-20310
Full detection coverage and IOCs for threats exploiting CVE-2026-20310 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp