CVE-2026-0809CWE-261

Weak KSeF token encoding in Streamsoft Prestiż

Medium · published March 12, 2026

CVSS v4.0
6.3
EPSS
0%
Percentile
16.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.3 · MEDIUM
Vector
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
EPSS
0.00259 · 16.5th percentile
Weakness
CWE-261 · Weak Encoding for Password
Published
2026-03-12T13:02Z
EPSS history
Timeline
  • 12 MAR 13:02Z
    Weak KSeF token encoding in Streamsoft Prestiż
    cvelistv5