What’s Vulnerable › Vulnerabilities
CVE-2026-0809: Weak KSeF token encoding in Streamsoft Prestiż
- Severity: medium (CVSS 6.3 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-12 · updated 2026-06-17
- Weakness: CWE-261
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 Prestiż: from 12.2.363.17 before 20.0.380.92 — fixed in 20.0.380.92
How to fix
Upgrade to a fixed version: Streamsoft Prestiż 20.0.380.92. Check the vendor advisory for mitigations.
References
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