Critical severity · published May 25, 2026
CVE-2026-9058
Improper Certificate Verification in Szafir SDK
9.3
CVSS
0.3%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SS
Szafir SDK · Krajowa Izba Rozliczeniowa
before 1.8.463.2 · source: vendor