How severe is CVE-2026-9058?

CVE-2026-9058 has a CVSS 4.0 base score of 9.3, rated critical severity.

Is CVE-2026-9058 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-9058?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-9058 have an EU (EUVD) identifier?

Yes. CVE-2026-9058 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31679.

When was CVE-2026-9058 published?

CVE-2026-9058 was published on 2026-05-25 and last updated on 2026-06-17.

CVE-2026-9058

CVE-2026-9058 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-393.

Key facts

Severity: Critical (CVSS 4.0 base score 9.3)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31679
Weakness: CWE-393
Published: 2026-05-25
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-9058?: 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.
How severe is CVE-2026-9058?: CVE-2026-9058 has a CVSS 4.0 base score of 9.3, rated critical severity.
Is CVE-2026-9058 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-9058?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-9058 have an EU (EUVD) identifier?: Yes. CVE-2026-9058 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31679.
When was CVE-2026-9058 published?: CVE-2026-9058 was published on 2026-05-25 and last updated on 2026-06-17.

References

Other CWE-393 vulnerabilities

CVE-2024-49117 — High (CVSS 8.8): Windows Hyper-V Remote Code Execution Vulnerability
CVE-2025-5987 — High (CVSS 8.1): A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library. If an attacker manages to exhaust…
CVE-2026-53092 — High (CVSS 7.8): In the Linux kernel, the following vulnerability has been resolved: bpf: Fix linked reg delta tracking when src_reg ==…
CVE-2025-24531 — Medium (CVSS 6.7): In OpenSC pam_pkcs11 before 0.6.13, pam_sm_authenticate() wrongly returns PAM_IGNORE in many error situations (such as…

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