Observable Timing Discrepancy in Tink-Java and Tink-Android ChunkedMacVerification

{
  "id": "fa3bf8d1e3cc8e48cd0eec451967e7b5bc98df8b6d828ca5807ceabb1805b16a",
  "url": "https://osv.dev/vulnerability/CVE-2026-15432",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Observable Timing Discrepancy in Tink-Java and Tink-Android ChunkedMacVerification",
    "summary": "When verifying a mac with a ChunkedMacVerification object, Tink compares the resulting tag with non constant time comparison. This potentially allows an attacker to use timinig information as a side channel in order to get information how many bytes of a given tag match the correct tag. This in turn could allow to find a correct tag bytewise.",
    "evidence": "osv:CVE-2026-15432",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-15432",
      "aliases": [
        "CVE-2026-15432"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/tink-crypto/tink-java",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "0be571737dae79cccf9ba93b6da7a05ff70d7545"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.21.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "VersionTextExtraction"
                  },
                  {
                    "cpe": "cpe:2.3:a:google:tink_java:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.21.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.20.0",
            "v1.19.0",
            "v1.18.0",
            "v1.17.0",
            "v1.16.0",
            "v1.15.0",
            "v1.14.0",
            "v1.13.0",
            "v1.12.0",
            "v1.11.0",
            "v1.8.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-15432.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.132819207Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15432.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-15432",
        "https://github.com/tink-crypto/tink-java/issues/75"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-208"
        ],
        "cna_assigner": "Google",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15432.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-15432",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513349,
  "published_at": "2026-07-21T16:42:12.113+00:00"
}