# CVE-2026-0809

## Summary

- **CVE ID:** CVE-2026-0809
- **Severity:** MEDIUM
- **CVSS Score:** 6.3 (CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-261
- **Published:** Mar 12, 2026
- **Last Modified:** Mar 12, 2026

## Description

Use of a custom token encoding algorithm in Streamsoft Prestiż software allows the value of the KSeF (Krajowy System e-Faktur) token to be guessed after analyzing how tokens with know values are encoded.

This issue was fixed in version 20.0.380.92.

## Affected Products

- Streamsoft — Streamsoft Prestiż (12.2.363.17)

## References

- [CNA](https://www.streamsoft.pl/streamsoft-prestiz/)
- [CNA](https://cert.pl/posts/2026/03/CVE-2026-0809)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.25%
- **EPSS Percentile:** 16.2

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._