CVE-2026-9058
Improper Certificate Verification in Szafir SDK
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.
INFO
Published Date :
May 25, 2026, 2:16 p.m.
Last Modified :
July 23, 2026, 12:18 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-9058
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | CRITICAL | 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update Szafir SDK to version 463 or later.
- Ensure certificate trust is properly validated.
- Verify signature validity using established trust.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-9058.
| URL | Resource |
|---|---|
| https://cert.pl/posts/2026/05/CVE-2026-9058 | |
| https://www.elektronicznypodpis.pl/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9058 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-9058
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-9058 vulnerability anywhere in the article.
-
cert.pl
Vulnerability in Szafir SDK software
Vulnerability in Szafir SDK software CVE ID CVE-2026-9058 Publication date 25 May 2026 Vendor Krajowa Izba Rozliczeniowa Product Szafir SDK Vulnerable versions All before 463 Vulnerability type (CWE) ... Read more
The following table lists the changes that have been made to the
CVE-2026-9058 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Changed Affected [{'vendor': 'Krajowa Izba Rozliczeniowa', 'product': 'Szafir SDK', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '463', 'versionType': 'custom'}], 'defaultStatus': 'unaffected'}] [{'vendor': 'Krajowa Izba Rozliczeniowa', 'product': 'Szafir SDK', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.8.463.2', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Changed Description Szafir SDK returns a success status code from the cryptographic digital signature verification process (i.e. /VerifyingTaskItem/Signature/VerificationResult/Result/@code == 0, "Positively verified") even when the trust status of the signer's certificate could not be established (i.e. /VerifyingTaskItem/Signature/VerificationResult/SigningCertificate/@certificateType == "nondetermined"). This causes consuming applications to incorrectly treat the signature as valid despite an unverified certificate chain, enabling authentication bypass and user impersonation. This issue was fixed in version 463. 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. Added CWE CWE-295 -
CVE Translated by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Added Translation Title: Szafir SDK de Krajowa Izba Rozliczeniowa, Description: El SDK de Szafir devuelve un código de estado de éxito del proceso de verificación de firma digital criptográfica (es decir, /VerifyingTaskItem/Signature/VerificationResult/Result/@code == 0, 'Verificado positivamente') incluso cuando el estado de confianza del certificado del firmante no pudo establecerse (es decir, /VerifyingTaskItem/Signature/VerificationResult/SigningCertificate/@certificateType == 'nondetermined'). Esto provoca que las aplicaciones consumidoras traten incorrectamente la firma como válida a pesar de una cadena de certificados no verificada, lo que permite la omisión de autenticación y la suplantación de identidad de usuario. Este problema se solucionó en la versión 463. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Krajowa Izba Rozliczeniowa', 'product': 'Szafir SDK', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '463', 'versionType': 'custom'}], 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-9058', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-26T15:57:55.171237Z'} -
New CVE Received by [email protected]
May. 25, 2026
Action Type Old Value New Value Added Description Szafir SDK returns a success status code from the cryptographic digital signature verification process (i.e. /VerifyingTaskItem/Signature/VerificationResult/Result/@code == 0, "Positively verified") even when the trust status of the signer's certificate could not be established (i.e. /VerifyingTaskItem/Signature/VerificationResult/SigningCertificate/@certificateType == "nondetermined"). This causes consuming applications to incorrectly treat the signature as valid despite an unverified certificate chain, enabling authentication bypass and user impersonation. This issue was fixed in version 463. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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 Added CWE CWE-393 Added CWE CWE-637 Added Reference https://cert.pl/posts/2026/05/CVE-2026-9058 Added Reference https://www.elektronicznypodpis.pl/