---
cve: "CVE-2026-20310"
severity: "CRITICAL"
cvss: 9.1
epss: "39%"
vendor: "Cisco"
kev: false
exploited: false
published: "2026-08-05 17:16:51"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T05:39:39+02:00"
---

# CVE-2026-20310

> 9.1 CRITICAL

## Beschreibung

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-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Hoch | good |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-59** — Improper Link Resolution Before File Access ('Link Following')
  The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

## Angriffsmuster (CAPEC)

- [CAPEC-17 — Using Malicious Files](https://capec.mitre.org/data/definitions/17.html) _(Severity: Very High)_
- [CAPEC-35 — Leverage Executable Code in Non-Executable Files](https://capec.mitre.org/data/definitions/35.html) _(Severity: Very High)_
- [CAPEC-76 — Manipulating Web Input to File System Calls](https://capec.mitre.org/data/definitions/76.html) _(Severity: Very High)_
- [CAPEC-132 — Symlink Attack](https://capec.mitre.org/data/definitions/132.html) _(Severity: High)_

## ATT&CK-Techniken

- [T1574.005 — Hijack Execution Flow: Executable Installer File Permissions](https://attack.mitre.org/techniques/T1574/005/)
- [T1574.010 — Hijack Execution Flow: Services File Permissions Weakness](https://attack.mitre.org/techniques/T1574/010/)
- [T1027.006 — Obfuscated Files or Information: HTML Smuggling](https://attack.mitre.org/techniques/T1027/006/)
- [T1027.009 — Obfuscated Files or Information: Embedded Payloads](https://attack.mitre.org/techniques/T1027/009/)
- [T1564.009 — Hide Artifacts: Resource Forking](https://attack.mitre.org/techniques/T1564/009/)
- [T1547.009 — Boot or Logon Autostart Execution:Shortcut Modification](https://attack.mitre.org/techniques/T1547/009/)

## Referenzen

- <https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K>
- <https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-20310) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_