{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:osslsigncode_project:osslsigncode:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.12"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "fac81646228a4d58aa9df41ac2b84c5a21d9d2d9"
            },
            {
              "fixed": "cbee1e723c5a8547302bd841ad9943ed8144db68"
            }
          ],
          "repo": "https://github.com/mtrojnar/osslsigncode",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-hx87-8754-xvh4"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-121",
      "CWE-787"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39853.json"
  },
  "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.",
  "id": "CVE-2026-39853",
  "modified": "2026-07-08T05:37:40.393963869Z",
  "published": "2026-04-09T15:50:26.548Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mtrojnar/osslsigncode/releases/tag/2.12"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39853.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-8754-xvh4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39853"
    },
    {
      "type": "FIX",
      "url": "https://github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd841ad9943ed8144db68"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification"
}