CVE-2026-0809

Name: CVE-2026-0809
Creator: NVD / NIST
Published: 2026-03-12T13:16:00.723+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.3/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-0809 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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.. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 4.0

6.3/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.25%

16.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-261

References

Timeline

Published: Mar 12, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-0809?

How severe is CVE-2026-0809?

CVE-2026-0809 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-0809?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-0809?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST