Vulnerability · Published May 25, 2026 · Assigned by CERT-PL
CVE-2026-9058Improper Certificate Verification in Szafir SDK
Critical 9.3
In plain English
A critical-severity improper certificate validation in Szafir SDK from Krajowa Izba Rozliczeniowa. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Official description
For untrusted certificates that contain the "Authority Information Access - caIssuers URI" extension, Szafir SDK will automatically download the parent CA certificate from the specified URL and will import it to its trust store as a "nonqualified" certificate. In such a case, Szafir SDK returns a success status code of 0 ("Positively verified") upon successful cryptographic verification and a certificate status of "nonqualified". For other types of untrusted certificates, Szafir SDK returns a success status code of 0 ("Positively verified") upon successful cryptographic verification and a certificate status of "nondetermined". This may lead integrating applications to incorrectly treat the digital signature as valid despite an untrusted certificate chain. This flaw enables authentication bypass and user impersonation: (1) in use-cases other than qualified certificate authentication, or (2) if the qualified certificate authentication use-case is not correctly implemented by the integrating application. This issue was fixed in version 1.8.463.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Krajowa Izba Rozliczeniowa | Szafir SDK | 0 – before 1.8.463.2 |
Weakness: CWE-637, CWE-393, CWE-295 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://cert.pl/posts/2026/05/CVE-2026-9058 third-party-advisory
- https://www.elektronicznypodpis.pl/ product