Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message_CVE-2026-23831

{
    "lastseen": "",
    "description": "Rekor is a software supply chain transparency log. In versions 1.4.3 and below, the entry implementation can panic on attacker-controlled input when canonicalizing a proposed entry with an empty spec.message, causing nil Pointer Dereference. Function validate() returns nil (success) when message is empty, leaving sign1Msg uninitialized, and Canonicalize() later dereferences v.sign1Msg.Payload. A malformed proposed entry of the cose/v0.0.1 type can cause a panic on a thread within the Rekor process. The thread is recovered so the client receives a 500 error message and service still continues, so the availability impact of this is minimal. This issue has been fixed in version 1.5.0.",
    "published": "2026-01-22T21:26:22.183Z",
    "modified": "2026-01-23T14:32:43.078Z",
    "type": "cve",
    "title": "Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message",
    "source": "GitHub_M",
    "references": "https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833\nhttps://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd\nhttps://github.com/sigstore/rekor/releases/tag/v1.5.0",
    "id": "CVE-2026-23831",
    "bulletinFamily": "",
    "cwe": [
        "CWE-476"
    ],
    "cvelist": null,
    "sourceData": "sigstore rekor < 1.5.0",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "rekor",
    "version": "< 1.5.0",
    "vendor": "sigstore",
    "ai_description": "",
    "ai_severity": "",
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    "ai_product": "",
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    "ai_score": 0
}