{"id":"DEBIAN-CVE-2026-39853","details":"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.","modified":"2026-09-14T17:03:10.284854717Z","published":"2026-04-09T16:16:31.233Z","upstream":["CVE-2026-39853"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-39853"}],"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-2026-39853.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-2026-39853.json"}},{"package":{"name":"osslsigncode","ecosystem":"Debian:14","purl":"pkg:deb/debian/osslsigncode?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12-1"}]}],"versions":["2.10-1","2.11-1","2.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39853.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:H/I:H/A:H"}]}