CVE-2026-57916: Arbitrary Path Execution via CPS URI in proCertum SmartSign

Severity: medium (CVSS 4.6 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-27 · updated 2026-10-24
Weakness: CWE-73

Description

proCertum SmartSign opens Certificate Practice Statement (CPS) URI without schema validation. An attacker can prepare arbitrary certificate with CPS URI pointing to a local executable file or any URL, sign a document with it, and send it to the victim. When the victim opens the document in the application, the specified file will be executed (or webpage will be opened). This issue was fixed in version 9.4.3.90.

Affected products

Asseco proCertum SmartSign: before 9.4.3.90 — fixed in 9.4.3.90

How to fix

Upgrade to a fixed version: Asseco proCertum SmartSign 9.4.3.90. Check the vendor advisory for mitigations.

References

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