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Cisco Catalyst SD-WAN Software Security Hardening Release: August 2026

criticalCVE-2026-20303CVE-2026-20304CVE-2026-20310CVE-2026-20312CVE-2026-20313
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class — Common Weakness Enumeration (CWE) — and assigned a single Common Vulnerabilities and Exposures identifier (CVE ID) to each CWE grouping. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K Security Impact Rating: Critical CVE: CVE-2026-20303,CVE-2026-20304,CVE-2026-20310,CVE-2026-20312,CVE-2026-20313

CSIRTS triage

What
Multiple internally discovered vulnerabilities in Catalyst SD-WAN Software grouped by Common Weakness Enumeration class.
Who is affected
All versions of Cisco Catalyst SD-WAN Software are affected.
Urgency
Critical severity; no active exploitation known but internal testing identified multiple vulnerability classes requiring immediate patching.
Action
Apply Cisco Catalyst SD-WAN Software updates immediately; no workarounds available.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source
Cisco Security Advisories (INTL · vendor-psirt · site)
Severity
critical
Published
2026-08-05
Exploitation
Not in CISA KEV at last sync

Original advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K?vs_f=Cisco%20Security%20Advisory%26vs_cat=Security%20Intelligence%26vs_type=RSS%26vs_p=Cisco%20Catalyst%20SD-WAN%20Software%20Security%20Hardening%20Release:%20August%202026%26vs_k=1

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Referenced CVEs

CVECSIRTS overviewExternal
CVE-2026-20303coverage & exploitation statusNVD · CVE.org
CVE-2026-20304coverage & exploitation statusNVD · CVE.org
CVE-2026-20310coverage & exploitation statusNVD · CVE.org
CVE-2026-20312coverage & exploitation statusNVD · CVE.org
CVE-2026-20313coverage & exploitation statusNVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Cisco Catalyst SD-WAN

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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