CVE-2026-26927: URL (HTTP Origin) call location spoofing in Szafir SDK Web

Severity: medium (CVSS 5.1 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-02 · updated 2026-10-26
Weakness: CWE-348

Description

Szafir SDK Web is a browser plug-in that can run SzafirHost application which download the necessary files when launched. In Szafir SDK Web it is possible to change the URL (HTTP Origin) of the application call location. An unauthenticated attacker can craft a website that is able to launch SzafirHost application with arbitrary arguments via Szafir SDK Web browser addon. No validation will be performed to check whether the address specified in `document_base_url` parameter is in any way related to the actual address of the calling web application. The URL address specified in `document_base_url` parameter is then shown in the application confirmation prompt. When a victim confirms the execution of the application, it will be called in the context of attacker's website URL and might download additional files and libraries from that website. When victim accepts the application execution for the URL showed in the confirmation prompt with the "remember" option before, the prompt won't be shown and the application will be called in the context of URL provided by the attacker without any interaction. This issue was fixed in version 0.0.17.4.

Affected products

Krajowa Izba Rozliczeniowa Szafir SDK Web: before 0.0.17.4 — fixed in 0.0.17.4

How to fix

Upgrade to a fixed version: Krajowa Izba Rozliczeniowa Szafir SDK Web 0.0.17.4. Check the vendor advisory for mitigations.

References

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