{"id":"CVE-2026-39853","aliases":["DEBIAN-CVE-2026-39853","EUVD-2026-20942","GHSA-hx87-8754-xvh4","UBUNTU-CVE-2026-39853"],"status":"published","title":"osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification","description":"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.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00166,"percentile":0.05872,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-121","CWE-787"],"published":"2026-04-09T15:50:26Z","modified":"2026-10-28T10:49:40Z","fixes":[{"ecosystem":"Debian:14","package":"osslsigncode","fixed_in":["2.12-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"osslsigncode","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"]},{"source":"osv","ecosystem":"Debian:13","package":"osslsigncode","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"]},{"source":"osv","ecosystem":"Debian:14","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12-1"}]}],"versions":["2.10-1","2.11-1","2.9-2"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.1-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.1-2build1","1.7.1-2ubuntu1","1.7.1-3"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1-1","2.2-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.5-4","2.8-2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"osslsigncode","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.9-2"]}],"products":[{"vendor":"mtrojnar","product":"osslsigncode"},{"vendor":"osslsigncode_project","product":"osslsigncode"}],"references":[{"url":"https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-8754-xvh4","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","report"]},{"url":"https://github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd841ad9943ed8144db68","tags":["x_refsource_MISC","Patch","fix","report"]},{"url":"https://github.com/mtrojnar/osslsigncode/releases/tag/2.12","tags":["x_refsource_MISC","Product","Release Notes","web","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39853.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39853","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-39853","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-39853","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-39853","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-39853","title":"osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification","description":"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.","status":"published","published":"2026-04-09T15:50:26.548Z","modified":"2026-04-09T16:15:19.583Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-121","CWE-787"],"updated_at":"2026-11-02T14:20:02.662847Z"}],"euvd":[{"id":"EUVD-2026-20942","description":"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.","status":"published","published":"2026-04-09T15:50:26Z","modified":"2026-04-09T16:15:19Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T19:24:30.741683Z"}],"nvd":[{"id":"CVE-2026-39853","description":"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.","status":"published","published":"2026-04-09T16:16:31.233Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-121","CWE-787"],"updated_at":"2026-11-02T14:12:13.902911Z"}],"osv":[{"id":"CVE-2026-39853","title":"osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification","description":"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.","status":"published","published":"2026-04-09T15:50:26.548Z","modified":"2026-10-28T10:49:40.202053455Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-121","CWE-787"],"updated_at":"2026-11-02T15:45:03.040464Z"},{"id":"DEBIAN-CVE-2026-39853","description":"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.","status":"published","published":"2026-04-09T16:16:31.233Z","modified":"2026-10-27T09:47:29.725708556Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:54.892385Z"},{"id":"UBUNTU-CVE-2026-39853","description":"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.","status":"published","published":"2026-04-09T16:16:00Z","modified":"2026-04-16T09:13:14Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T16:56:16.686388Z"}]}}