{
  "cveId": "CVE-2026-6331",
  "url": "https://patchblox.com/security/cve/CVE-2026-6331",
  "summary": "CVE-2026-6331 is fixed in wolfssl on 1 platform, first by DEBIAN-CVE-2026-6331, released July 18, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "wolfssl: HMAC zero-length tag forgery in EVP_DigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC...",
  "description": "HMAC zero-length tag forgery in EVP_DigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility HMAC verify path the supplied signature length was only checked as not exceeding the MAC length, so a zero-length or otherwise truncated tag could pass verification. The fix requires the supplied tag length to exactly equal the MAC length and rejects a zero-length MAC, so a forged short or empty tag is no longer accepted.",
  "published": "2026-06-25T22:17:03Z",
  "severity": "high",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
  "epss": 0.0019,
  "epssPercentile": 0.08727,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "wolfssl",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.5.4-2\u002Bdeb12u3",
      "fix": "DEBIAN-CVE-2026-6331",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-6331",
      "released": "2026-07-18T12:42:52Z"
    },
    {
      "platform": "linux",
      "product": "wolfssl",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.7.2-0.1\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-6331",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-6331",
      "released": "2026-07-18T12:42:52Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-07T18:46:35Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}