CVE-2026-0809 is a medium-severity vulnerability affecting Streamsoft Prestiż software, stemming from a weak custom token encoding algorithm. This flaw allows an attacker to guess KSeF (Krajowy System e-Faktur) token values by analyzing how known tokens are encoded. With a CVSS 4.0 score of 6.3, this vulnerability is network-exploitable with low attack complexity and requires no privileges or user interaction, potentially leading to unauthorized access. There is currently no evidence of active exploitation, public exploit code, or significant community discussion, and it is not listed on CISA's Known Exploited Vulnerabilities catalog.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
| Streamsoft | Streamsoft Prestiż | >= 12.2.363.17, < 20.0.380.92CNA affecteddefault unaffected |
CVSS version used by this source: 4.0
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
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.