Weak KSeF token encoding in Streamsoft Prestiż
Published Mar 12, 2026
6.3
MEDIUMCVSS 4.0
EPSS 0.25%
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
-
- Version 12.2.363.17StatusaffectedConstraints<20.0.380.92
- Version
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 |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
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
1 other source (NVD) ▾
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
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Mar 12, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.25% (0.00249) | 14.63th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.25% (0.00249) | 15.90th | v5 (v2026.06.15) |
| Mar 13, 2026 | 0.04% (0.00041) | 12.22th | v4 (v2025.03.14) |
References (2)
- https://cert.pl/posts/2026/03/CVE-2026-0809 third-party-advisory
- https://www.streamsoft.pl/streamsoft-prestiz/ product
| Link | Providers | Tags |
|---|---|---|
| https://cert.pl/posts/2026/03/CVE-2026-0809 | third-party-advisory | |
| https://www.streamsoft.pl/streamsoft-prestiz/ | product |
Change history (0)
No recorded changes yet.