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CVE-2026-8463

Full vulnerability record from the local CVENow database.

Description

Crypt::Argon2 versions from 0.017 before 0.031 for Perl perform a heap out-of-bounds read in argon2_verify on empty encoded input. The auto-detect form of argon2_verify passes encoded_len - 1 as the length argument to memchr without checking that encoded_len is non-zero. When the encoded string is empty, the size_t subtraction underflows to SIZE_MAX and memchr scans adjacent heap memory looking for a '$' separator byte. A caller that invokes argon2_verify against a stored hash that may legitimately be empty (for example a placeholder row or a NULL column materialised as an empty string) reads out-of-bounds heap memory, which can crash the process or leak the position of an adjacent '$' byte into subsequent parsing.

Severity
MEDIUM
CVSS score
5.3 (v3.1)
Vulnerability status
Analyzed
Source identifier
9b29abf9-4ab0-4765-b253-1875cd9b441e
Published
2026-05-13 14:18:17.140000
Last modified
2026-10-26 14:10:00.130000
View original CVE JSON
{
  "id": "CVE-2026-8463",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-05-13T14:18:17.140",
  "lastModified": "2026-10-26T14:10:00.130",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Crypt::Argon2 versions from 0.017 before 0.031 for Perl perform a heap out-of-bounds read in argon2_verify on empty encoded input.\n\nThe auto-detect form of argon2_verify passes encoded_len - 1 as the length argument to memchr without checking that encoded_len is non-zero. When the encoded string is empty, the size_t subtraction underflows to SIZE_MAX and memchr scans adjacent heap memory looking for a '$' separator byte.\n\nA caller that invokes argon2_verify against a stored hash that may legitimately be empty (for example a placeholder row or a NULL column materialised as an empty string) reads out-of-bounds heap memory, which can crash the process or leak the position of an adjacent '$' byte into subsequent parsing."
    },
    {
      "lang": "es",
      "value": "Las versiones de Crypt::Argon2 desde la 0.017 anteriores a la 0.031 para Perl realizan una lectura fuera de límites del heap en argon2_verify con una entrada codificada vacía.\n\nLa forma de autodetección de argon2_verify pasa encoded_len - 1 como argumento de longitud a memchr sin verificar que encoded_len no sea cero. Cuando la cadena codificada está vacía, la resta de size_t subdesborda a SIZE_MAX y memchr escanea memoria heap adyacente buscando un byte separador ’$’.\n\nUn llamador que invoca argon2_verify contra un hash almacenado que puede estar legítimamente vacío (por ejemplo, una fila de marcador de posición o una columna NULL materializada como una cadena vacía) lee memoria heap fuera de límites, lo que puede bloquear el proceso o filtrar la posición de un byte ’$’ adyacente en el análisis posterior."
    }
  ],
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "vendor": "LEONT",
          "product": "Crypt::Argon2",
          "defaultStatus": "unaffected",
          "collectionURL": "https://cpan.org/modules",
          "packageName": "Crypt-Argon2",
          "programFiles": [
            "lib/Crypt/Argon2.xs"
          ],
          "programRoutines": [
            {
              "name": "Crypt::Argon2::argon2_verify"
            }
          ],
          "repo": "https://github.com/Leont/crypt-argon2",
          "versions": [
            {
              "version": "0.017",
              "lessThan": "0.031",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      },
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-13T17:19:23.875232Z",
          "id": "CVE-2026-8463",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-126"
        },
        {
          "lang": "en",
          "value": "CWE-191"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:leont:crypt\\:\\:argon2:*:*:*:*:*:perl:*:*",
              "versionStartIncluding": "0.017",
              "versionEndExcluding": "0.031",
              "matchCriteriaId": "665F8DDD-FC30-44AE-8E88-5292B014AB76"
            }
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        }
      ]
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  ],
  "references": [
    {
      "url": "https://github.com/Leont/crypt-argon2/commit/92eac03ce63d541e0ead7ea5a89b9b67ce0c0e64.patch",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://metacpan.org/release/LEONT/Crypt-Argon2-0.031/changes",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/05/13/4",
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ]
    }
  ]
}