# CVE-2026-44088: Remote Code Execution in SzafirHost

> Attackers can achieve remote code execution by crafting a JAR file that bypasses signature verification due to inconsistent parsing logic.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L`)
- **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:** 15 May 2026
- **Updated:** 15 May 2026
- **Also known as:** GHSA-j8f8-frc5-vgc6

## What is CVE-2026-44088?

CVE-2026-44088 is a high-severity code injection vulnerability in Krajowa Izba Rozliczeniowa SzafirHost, published on 15 May 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

SzafirHost verifies the signature of the downloaded JAR file using class JarInputStream (reading from the beginning of the file), but loads classes using class JarFile/URLClassLoader (reading the Central Directory from the end). It can lead to remote code execution by allowing an attacker to combine a genuine, signed JAR file with a malicious ZIP file, causing the verification to pass but the malicious class to be loaded.

This issue was fixed in version 1.2.1.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-44088?


## How do I fix CVE-2026-44088?

No fix has been published for CVE-2026-44088 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-44088 being exploited?

There is no known exploitation of CVE-2026-44088 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44088 and fix it if it is affected.

What it is: CVE-2026-44088 is a high-severity code injection vulnerability in Krajowa Izba Rozliczeniowa SzafirHost, published on 15 May 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-2026-44088 in the wild and no public exploit code.

Affected product: Krajowa Izba Rozliczeniowa SzafirHost. 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-2026-44088/ (Markdown: https://insights.sbomify.com/CVE-2026-44088/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44088
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44088
- OSV: https://osv.dev/vulnerability/CVE-2026-44088

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-44088/
Summaries are generated and may contain mistakes; the official description above is the record.