# CVE-2026-97155: Security feature bypass in Folio Client

> Any website can invoke Fabasoft Folio Client functions due to missing origin restrictions, allowing unauthorized document access and synchronization.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 24 Sep 2026
- **Updated:** 26 Sep 2026
- **Also known as:** GHSA-9hhv-69vm-5vcw

## What is CVE-2026-97155?

CVE-2026-97155 is a medium-severity vulnerability in Fabasoft Folio Client, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Fabasoft Folio Client before 2026, a locally installed component that communicates with the Fabasoft browser extension via web messaging, does not restrict which web origins may invoke its functions by default. The registry value VALIDDOMAINS, which limits permitted origins, was optional and empty by default, resulting in all domains being trusted. As a consequence, any website visited by a user with the Folio Client and browser extension installed could invoke client functions, e.g., related to downloading documents, opening documents, and synchronizing files. The first fixed builds are Fabasoft Folio Client 2026 (Build 26.0.0.10) and Fabasoft Folio Client 2026 April Release (Build 26.4.0.76). This client is, for example, shipped with Fabasoft eGov-Suite.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-97155?


## How do I fix CVE-2026-97155?

No fix has been published for CVE-2026-97155 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-97155 being exploited?

There is no known exploitation of CVE-2026-97155 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97155 and fix it if it is affected.

What it is: CVE-2026-97155 is a medium-severity vulnerability in Fabasoft Folio Client, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-97155 in the wild and no public exploit code.

Affected product: Fabasoft Folio Client. 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-2026-97155/ (Markdown: https://insights.sbomify.com/CVE-2026-97155/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97155
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97155
- OSV: https://osv.dev/vulnerability/CVE-2026-97155

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97155/
Summaries are generated and may contain mistakes; the official description above is the record.