{"id":"DEBIAN-CVE-2026-39855","details":"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 \u003e= 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.","modified":"2026-09-14T17:03:10.289088143Z","published":"2026-04-09T17:16:29.140Z","upstream":["CVE-2026-39855"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-39855"}],"affected":[{"package":{"name":"osslsigncode","ecosystem":"Debian:12","purl":"pkg:deb/debian/osslsigncode?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"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"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39855.json"}},{"package":{"name":"osslsigncode","ecosystem":"Debian:13","purl":"pkg:deb/debian/osslsigncode?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10-1","2.11-1","2.12-1","2.13-1","2.13-2","2.14-1","2.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39855.json"}},{"package":{"name":"osslsigncode","ecosystem":"Debian:14","purl":"pkg:deb/debian/osslsigncode?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.13-1"}]}],"versions":["2.10-1","2.11-1","2.12-1","2.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39855.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}