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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Streamsoft Streamsoft Prestiż unaffected
Version Status Constraints
12.2.363.17 affected < 20.0.380.92

No data.

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://cert.pl/posts/2026/03/CVE-2026-0809 cve-icon cve-icon
https://www.streamsoft.pl/streamsoft-prestiz/ cve-icon cve-icon
History

Thu, 12 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 12 Mar 2026 13:15:00 +0000

Type Values Removed Values Added
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.
Title Weak KSeF token encoding in Streamsoft Prestiż
Weaknesses CWE-261
References
Metrics cvssV4_0

{'score': 6.3, '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-03-12T14:04:53.073Z

Reserved: 2026-01-09T14:56:38.137Z

Link: CVE-2026-0809

cve-icon Vulnrichment

Updated: 2026-03-12T14:04:22.959Z

cve-icon NVD

Status : Received

Published: 2026-03-12T13:16:00.723

Modified: 2026-03-12T13:16:00.723

Link: CVE-2026-0809

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses