{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "CryptoLib",
          "vendor": "nasa",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.4.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station. Prior to version 1.4.3, in base64urlDecode, padding-stripping dereferences input[inputLen - 1] before checking that inputLen \u003e 0 or that input != NULL. For inputLen == 0, this becomes an OOB read at input[-1], potentially crashing the process. If input == NULL and inputLen == 0, it dereferences NULL - 1. This issue has been patched in version 1.4.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.7,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125: Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-10T00:11:18.877Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8"
        },
        {
          "name": "https://github.com/nasa/CryptoLib/releases/tag/v1.4.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nasa/CryptoLib/releases/tag/v1.4.3"
        }
      ],
      "source": {
        "advisory": "GHSA-wc29-5hw7-mpj8",
        "discovery": "UNKNOWN"
      },
      "title": "CryptoLib has an out-of-bounds read and crash vulnerability when decoding an empty Base64url string"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-21899",
    "datePublished": "2026-01-10T00:11:18.877Z",
    "dateReserved": "2026-01-05T17:24:36.931Z",
    "dateUpdated": "2026-01-10T00:11:18.877Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-21899\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-01-10T01:16:18.113\",\"lastModified\":\"2026-01-10T01:16:18.113\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station. Prior to version 1.4.3, in base64urlDecode, padding-stripping dereferences input[inputLen - 1] before checking that inputLen \u003e 0 or that input != NULL. For inputLen == 0, this becomes an OOB read at input[-1], potentially crashing the process. If input == NULL and inputLen == 0, it dereferences NULL - 1. This issue has been patched in version 1.4.3.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L\",\"baseScore\":4.7,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":1.2,\"impactScore\":3.4}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"references\":[{\"url\":\"https://github.com/nasa/CryptoLib/releases/tag/v1.4.3\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}