CVE-2026-39856

MEDIUM EPSS 4.0%
Published Apr 9, 20262mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Apr 9, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.13, an out-of-bounds read vulnerability exists in osslsigncode version 2.12 and earlier in the PE page-hash computation code (pe_page_hash_calc()). When processing PE sections for page hashing, the function uses PointerToRawData and SizeOfRawData values from section headers without validating that the referenced region lies within the mapped file. An attacker can craft a PE file with section headers that point beyond the end of the file. When osslsigncode computes page hashes for such a file, it may attempt to hash data from an invalid memory region, causing an out-of-bounds read and potentially crashing the process. The vulnerability can be triggered while signing a malicious PE file with page hashing enabled (-ph), or while verifying a malicious signed PE file that already contains page hashes. Verification of an already signed file does not require the verifier to pass -ph. This vulnerability is fixed in 2.13.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
4.0% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 1

VendorProductVersionRange
osslsigncode_projectosslsigncode* <2.13

References 3

  • github.com https://github.com/mtrojnar/osslsigncode/commit/92f8761b4770f76a36731969b5040ce3b9a09570
    Patch
  • github.com https://github.com/mtrojnar/osslsigncode/releases/tag/2.13
    ProductRelease Notes
  • github.com https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-rjrx-chvw-8jw8
    PatchVendor Advisory

Remediation

  • github.com https://github.com/mtrojnar/osslsigncode/commit/92f8761b4770f76a36731969b5040ce3b9a09570
    Patch
  • github.com https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-rjrx-chvw-8jw8
    PatchVendor Advisory