# CVE-2026-4853: Path traversal in JetBackup – Backup, Restore & Migrate

> Authenticated administrators can delete arbitrary directories via path traversal in the fileName parameter, causing severe site disruption.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Apr 2026
- **Updated:** 17 Apr 2026
- **Also known as:** GHSA-8cfg-qq42-h3w8

## What is CVE-2026-4853?

CVE-2026-4853 is a medium-severity path traversal vulnerability in backupguard JetBackup – Backup, Restore & Migrate, published on 17 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The JetBackup – Backup, Restore & Migrate plugin for WordPress is vulnerable to Path Traversal leading to Arbitrary Directory Deletion in versions up to and including 3.1.19.8. This is due to insufficient input validation on the fileName parameter in the file upload handler. The plugin sanitizes the fileName parameter using sanitize_text_field(), which removes HTML tags but does not prevent path traversal sequences like '../'. The unsanitized filename is then directly concatenated in Upload::getFileLocation() without using basename() or validating the resolved path stays within the intended directory. When an invalid file is uploaded, the cleanup logic  calls dirname() on the traversed path and passes it to Util::rm(), which recursively deletes the entire resolved directory. This makes it possible for authenticated attackers with administrator-level access to traverse outside the intended upload directory and trigger deletion of critical WordPress directories such as wp-content/plugins, effectively disabling all installed plugins and causing severe site disruption.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-4853?


## How do I fix CVE-2026-4853?

No fix has been published for CVE-2026-4853 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4853 being exploited?

There is no known exploitation of CVE-2026-4853 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4853 and fix it if it is affected.

What it is: CVE-2026-4853 is a medium-severity path traversal vulnerability in backupguard JetBackup – Backup, Restore & Migrate, published on 17 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-4853 in the wild and no public exploit code.

Affected product: backupguard JetBackup – Backup, Restore & Migrate. 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-2026-4853/ (Markdown: https://insights.sbomify.com/CVE-2026-4853/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4853
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4853
- OSV: https://osv.dev/vulnerability/CVE-2026-4853

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4853/
Summaries are generated and may contain mistakes; the official description above is the record.