CVE-2026-71888

{
  "etk_id": "ETK-2026-438",
  "cve_id": "CVE-2026-71888",
  "display_id": "CVE-2026-71888",
  "ghsa_id": "GHSA-j453-27jp-4cph",
  "euvd_id": "EUVD-2026-91991",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Bouncy Castle CMS authenticated-attribute integrity bypass",
  "summary": "Affected Bouncy Castle CMS streaming parsers can expose authenticated-attribute values that were not covered by the message integrity check. An attacker able to modify a CMS AuthenticatedData message in transit could influence authorization, routing, or labeling decisions if the receiving application relies on those attributes. The message content itself remains integrity-protected.",
  "mitigation": "Upgrade bcpkix and bcutil to 1.86 or later, or bcpkix-lts8on and bcutil-lts8on to 2.73.13 or later. For FIPS deployments, update bcpkix-fips to 1.0.13, 2.0.13, or 2.1.13 for the applicable branch, and bcutil-fips to 2.0.8 or 2.1.8 for the applicable branch.",
  "vendor": "Legion of the Bouncy Castle Inc.",
  "product": "BC-JAVA",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, < 1.86"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "1.86"
      ],
      "package_name": "bcpkix",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.70, < 1.86"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "1.86"
      ],
      "package_name": "bcutil",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.73.0, < 2.73.13"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "2.73.13"
      ],
      "package_name": "bcpkix-lts8on",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.73.0, < 2.73.13"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "2.73.13"
      ],
      "package_name": "bcutil-lts8on",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.0.0, < 1.0.13",
        ">= 2.0.0, < 2.0.13",
        ">= 2.1.0, < 2.1.13"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "1.0.13",
        "2.0.13",
        "2.1.13"
      ],
      "package_name": "bcpkix-fips",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.0.0, < 2.0.8",
        ">= 2.1.0, < 2.1.8"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "2.0.8",
        "2.1.8"
      ],
      "package_name": "bcutil-fips",
      "purl": null
    }
  ],
  "cwes": [
    354
  ],
  "cvss_score": 8.7,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber",
  "epss_score": 0.0011,
  "epss_percentile": 0.0131,
  "epss_asof": "2026-10-20",
  "automation": "deterministic",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 11.87303895,
  "t0_at": "2026-10-03T08:36:12.960000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-03T08:36:12.960000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-03T08:36:12.960000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-71888"
    }
  }
}