CVE-2026-39856 | mtrojnar osslsigncode up to 2.12 pe_page_hash_calc PointerToRawData/SizeOfRawData out-of-bounds (GHSA-rjrx-chvw-8jw8)

VDB-356631 · CVE-2026-39856 · GHSA-RJRX-CHVW-8JW8 MTROJNAR OSSLSIGNCODE UP TO 2.12 PE_PAGE_HASH_CALC POINTERTORAWDATA/SIZEOFRAWDATA OUT-OF-BOUNDS HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.1 $0-$5k 1.16+ Summaryinfo A vulnerability identified as problematic has been detected in mtrojnar osslsigncode up to 2.12. Affected by this vulnerability is the function pe_page_hash_calc. Performing a manipulation of the argument PointerToRawData/SizeOfRawData results in out-of-bounds. This vulnerability is identified as CVE-2026-39856. The attack is only possible with local access. There is not any exploit available. You should upgrade the affected component. Detailsinfo A vulnerability was found in mtrojnar osslsigncode up to 2.12. It has been classified as problematic. This affects the function pe_page_hash_calc. The manipulation of the argument PointerToRawData/SizeOfRawData with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. The summary by CVE is: 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. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-39856 since 04/07/2026. The exploitability is told to be easy. Attacking locally is a requirement. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. Upgrading to version 2.13 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 92f8761b4770f76a36731969b5040ce3b9a09570 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Vendor mtrojnar Name osslsigncode Version 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 License open-source Website Product: https://github.com/mtrojnar/osslsigncode/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 4.1 VulDB Meta Temp Score: 4.1 VulDB Base Score: 2.8 VulDB Temp Score: 2.7 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 5.5 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Out-of-bounds CWE: CWE-125 / CWE-119 CAPEC: 🔒 ATT&CK: 🔒 Physical: Partially Local: Yes Remote: Partially Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: osslsigncode 2.13 Patch: 92f8761b4770f76a36731969b5040ce3b9a09570 Timelineinfo 04/07/2026 CVE reserved 04/09/2026 +2 days Advisory disclosed 04/09/2026 +0 days VulDB entry created 04/09/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-rjrx-chvw-8jw8 Status: Confirmed CVE: CVE-2026-39856 (🔒) GCVE (CVE): GCVE-0-2026-39856 GCVE (VulDB): GCVE-100-356631 Entryinfo Created: 04/09/2026 19:51 Changes: 04/09/2026 19:51 (69) Complete: 🔍 Cache ID: 99:786:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸