CVE-2026-39853
7.8 · HIGHOverview
CVE-2026-39853 is a high-severity vulnerability affecting osslsigncode_project osslsigncode. It was published on April 9, 2026 and has a CVSS 3.1 base score of 7.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical Description
osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.12, A stack buffer overflow vulnerability exists in osslsigncode in several signature verification paths. During verification of a PKCS#7 signature, the code copies the digest value from a parsed SpcIndirectDataContent structure into a fixed-size stack buffer (mdbuf[EVP_MAX_MD_SIZE], 64 bytes) without validating that the source length fits within the destination buffer. This pattern is present in the verification handlers for PE, MSI, CAB, and script files. An attacker can craft a malicious signed file with an oversized digest field in SpcIndirectDataContent. When a user verifies such a file with osslsigncode verify, the unbounded memcpy can overflow the stack buffer and corrupt adjacent stack state. This vulnerability is fixed in 2.12.
Remediation
Check the references section for vendor advisories and patches from osslsigncode_project. Update osslsigncode to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| osslsigncode_project | osslsigncode | >= 0, < 2.12 | Affected |
Frequently Asked Questions
What is CVE-2026-39853?
CVE-2026-39853 is a high-severity vulnerability affecting osslsigncode_project osslsigncode. It was published on April 9, 2026 and has a CVSS 3.1 base score of 7.8 (HIGH).
How severe is CVE-2026-39853?
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-39853?
Check the references section for vendor advisories and patches from osslsigncode_project. Update osslsigncode to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-39853?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-39853 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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