CVE-2026-9058: Improper Certificate Verification in Szafir SDK

Severity: critical (CVSS 9.3 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: 2026-05-25 · updated 2026-07-23
Weakness: CWE-295

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

Krajowa Izba Rozliczeniowa Szafir SDK: before 1.8.463.2 — fixed in 1.8.463.2

How to fix

Upgrade to a fixed version: Krajowa Izba Rozliczeniowa Szafir SDK 1.8.463.2. Check the vendor advisory for mitigations.

References

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