CryptoLib has an out-of-bounds read and crash vulnerability when decoding an empty Base64url string_CVE-2026-21899

{
    "lastseen": "",
    "description": "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 > 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.",
    "published": "2026-01-10T00:11:18.877Z",
    "modified": "2026-01-10T00:11:18.877Z",
    "type": "cve",
    "title": "CryptoLib has an out-of-bounds read and crash vulnerability when decoding an empty Base64url string",
    "source": "GitHub_M",
    "references": "https://github.com/nasa/CryptoLib/security/advisories/GHSA-wc29-5hw7-mpj8\nhttps://github.com/nasa/CryptoLib/releases/tag/v1.4.3",
    "id": "CVE-2026-21899",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125"
    ],
    "cvelist": null,
    "sourceData": "nasa CryptoLib < 1.4.3",
    "sourceHref": "",
    "cvss": {
        "score": 4.7,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
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        "privilegesRequired": "",
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        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "CryptoLib",
    "version": "< 1.4.3",
    "vendor": "nasa",
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    "ai_score": 0
}