# CVE-2026-57917: Improper Restriction of XML External Entity Reference in proCertum SmartSign

> Attackers can trigger SSRF and read local files by crafting signature files that exploit XML External Entity parsing in proCertum SmartSign.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** GHSA-fqfw-hf3f-2q4c

## What is CVE-2026-57917?

CVE-2026-57917 is a medium-severity vulnerability in Asseco proCertum SmartSign, published on 27 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

proCertum SmartSign parses external XML entities from arbitrary crafted signature files, enabling SSRF and potentially allowing the reading of local files, depending on the parser's configuration. The XML External Entity (XXE) vulnerability is triggered simply by previewing a file in the file selection window, before the victim clicks “Open”.

This issue was fixed in version 9.4.3.90.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2026-57917?


## How do I fix CVE-2026-57917?

No fix has been published for CVE-2026-57917 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57917 being exploited?

There is no known exploitation of CVE-2026-57917 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57917 and fix it if it is affected.

What it is: CVE-2026-57917 is a medium-severity vulnerability in Asseco proCertum SmartSign, published on 27 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-57917 in the wild and no public exploit code.

Affected product: Asseco proCertum SmartSign. 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-2026-57917/ (Markdown: https://insights.sbomify.com/CVE-2026-57917/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57917
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57917
- OSV: https://osv.dev/vulnerability/CVE-2026-57917

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-57917/
Summaries are generated and may contain mistakes; the official description above is the record.