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

> Attackers can exploit improper link resolution to access or modify files on Cisco Catalyst SD-WAN Controller and Manager systems.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-fhhx-46fx-737r

## What is CVE-2026-20310?

CVE-2026-20310 is a critical path traversal vulnerability in Cisco Catalyst SD-WAN Controller, published on 5 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official 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.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-20310?


## How do I fix CVE-2026-20310?

No fix has been published for CVE-2026-20310 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20310 being exploited?

There is no known exploitation of CVE-2026-20310 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20310 and fix it if it is affected.

What it is: CVE-2026-20310 is a critical path traversal vulnerability in Cisco Catalyst SD-WAN Controller, published on 5 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-20310 in the wild and no public exploit code.

Affected product: Cisco Catalyst SD-WAN Controller. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-20310/ (Markdown: https://insights.sbomify.com/CVE-2026-20310/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20310
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20310
- OSV: https://osv.dev/vulnerability/CVE-2026-20310

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20310/
Summaries are generated and may contain mistakes; the official description above is the record.