osslsigncode — security advisory
osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.13, an integer underflow vulnerability exists in osslsigncode version 2.12 and earlier in the PE page-hash computation code (pe_page_hash_calc()). When page hash processing is performed on a PE file, the function subtracts hdrsize from pagesize without first validating that pagesize >= hdrsize. If a malicious PE file sets SizeOfHeaders (hdrsize) larger than SectionAlignment (pagesize), the subtraction underflows and produces a very large unsigned length. The code allocates a zero-filled buffer of pagesize bytes and then attempts to hash pagesize - hdrsize bytes from that buffer. After the underflow, this results in an out-of-bounds read from the heap and can crash 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.
- Products
- osslsigncode
- Affected versions
- 2.10-1, 2.11-1, 2.12-1, 2.13-1, 2.13-2, 2.14-1, 2.5-4, 2.8-1, 2.8-2, 2.9-1, 2.9-1~bpo12+1, 2.9-2
- Fixed versions
- 2.13-1
- CVEs
- CVE-2026-39855
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:48 UTC · Revision 2
Source evidence
osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.13, an integer underflow vulnerability exists in osslsigncode version 2.12 and earlier in the PE page-hash computation code (pe_page_hash_calc()). When page hash processing is performed on a PE file, the function subtracts hdrsize from pagesize without first validating that pagesize >= hdrsize. If a malicious PE file sets SizeOfHeaders (hdrsize) larger than SectionAlignment (pagesize), the subtraction underflows and produces a very large unsigned length. The code allocates a zero-filled buffer of pagesize bytes and then attempts to hash pagesize - hdrsize bytes from that buffer. After the underflow, this results in an out-of-bounds read from the heap and can crash 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.
osv:DEBIAN-CVE-2026-39855
osslsigncode
Fixed versions: Not specified
osslsigncode
Fixed versions: Not specified
osslsigncode
Fixed versions: 2.13-1
Complete source record
{
"id": "143d778a5db530a0fc41d86b569fb507d42d7ca3ba523c0f684ea333b6d6351c",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-39855",
"method": "structured",
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"title": "DEBIAN-CVE-2026-39855",
"summary": "osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.13, an integer underflow vulnerability exists in osslsigncode version 2.12 and earlier in the PE page-hash computation code (pe_page_hash_calc()). When page hash processing is performed on a PE file, the function subtracts hdrsize from pagesize without first validating that pagesize >= hdrsize. If a malicious PE file sets SizeOfHeaders (hdrsize) larger than SectionAlignment (pagesize), the subtraction underflows and produces a very large unsigned length. The code allocates a zero-filled buffer of pagesize bytes and then attempts to hash pagesize - hdrsize bytes from that buffer. After the underflow, this results in an out-of-bounds read from the heap and can crash 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.",
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"modified": "2026-10-27T09:47:35.894918415Z",
"provider": "osv",
"upstream": [
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],
"references": [
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"source_id": "core-osv",
"document_id": 461245,
"published_at": "2026-04-09T17:16:29.14+00:00"
}