{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.23",
        "name": "wolfssl",
        "purl": "pkg:apk/alpine/wolfssl?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.9.1-r0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "Alpine:v3.24",
        "name": "wolfssl",
        "purl": "pkg:apk/alpine/wolfssl?arch=source"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.9.1-r0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge CMAC tags. The function wc_CmacUpdate used the guard `if (cmac-\u003etotalSz != 0)` to skip XOR-chaining on the first block (where digest is all-zeros and the XOR is a no-op). However, totalSz is word32 and wraps to zero after 2^28 block flushes (4 GiB), causing the guard to erroneously discard the live CBC-MAC chain state. Any two messages sharing a common suffix beyond the 4 GiB mark then produce identical CMAC tags, enabling a zero-work prefix-substitution forgery. The fix removes the guard, making the XOR unconditional; the no-op property on the first block is preserved because digest is zero-initialized by wc_InitCmac_ex.",
  "id": "ALPINE-CVE-2026-5477",
  "modified": "2026-11-03T06:18:01.705484900Z",
  "published": "2026-04-10T06:16:05.243Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security.alpinelinux.org/vuln/CVE-2026-5477"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-5477"
  ]
}