# CVE-2026-75592: Kirby: Access to image files outside of the site root via path traversal in the media handling

> Remote attackers can access and delete image files in sibling directories via path traversal in Kirby CMS media handling, exposing internal site data.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Aug 2026
- **Updated:** 1 Sep 2026
- **Also known as:** GHSA-6j4c-mgqr-qv76

## What is CVE-2026-75592?

CVE-2026-75592 is a medium-severity path traversal vulnerability in getkirby kirby, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kirby is an open-source content management system. Prior to 4.9.5 and 5.5.2, depending on the release line, Kirby's media handler used incomplete filesystem containment checks in src/Filesystem/Dir.php and src/Filesystem/F.php through Kirby\Filesystem\Dir::realpath() and Kirby\Filesystem\F::realpath(). The checks accepted a sibling directory whose path shared the intended root's string prefix, such as /var/www/site2 next to /var/www/site, because they did not require an exact match or a DIRECTORY_SEPARATOR boundary. A remote attacker could use Kirby\Cms\Media::thumb() to create and access thumbnails from image files in a PHP-readable sibling directory when that directory contained a valid .json thumbnail job file, potentially exposing staging sites, backups, or other internal sites and deleting the job file during processing. This issue is fixed in versions 4.9.5 and 5.5.2.

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

## Which versions are affected by CVE-2026-75592?

4 open source packages ship an affected version, including getkirby/cms.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `getkirby/cms` | Packagist | All versions | 4.9.5 |
| `getkirby/cms` | Packagist | All versions | 4.9.5 |
| `getkirby/cms` | Packagist | From 5.0.0 | 5.5.2 |
| `getkirby/cms` | Packagist | From 5.0.0 | 5.5.2 |

## How do I fix CVE-2026-75592?

Upgrade getkirby/cms to a fixed version for your release line: 4.9.5 or 5.5.2.

## Is CVE-2026-75592 being exploited?

There is no known exploitation of CVE-2026-75592 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75592 and fix it if it is affected.

What it is: CVE-2026-75592 is a medium-severity path traversal vulnerability in getkirby kirby, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-75592 in the wild and no public exploit code.

Affected packages and fixed versions:
- getkirby/cms (Packagist): affected all versions; fixed in 4.9.5
- getkirby/cms (Packagist): affected all versions; fixed in 4.9.5
- getkirby/cms (Packagist): affected from 5.0.0; fixed in 5.5.2
- getkirby/cms (Packagist): affected from 5.0.0; fixed in 5.5.2

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-2026-75592/ (Markdown: https://insights.sbomify.com/CVE-2026-75592/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75592
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75592
- OSV: https://osv.dev/vulnerability/CVE-2026-75592

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75592/
Summaries are generated and may contain mistakes; the official description above is the record.