CVE-2026-4296 Incorrect Regular Expression vulnerability in GitHub Enterprise Server allowed unauthorized access to user accounts via OAuth callback URL validation bypass

[
  {
    "vendor": "GitHub",
    "product": "Enterprise Server",
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        "lessThanOrEqual": "3.14.25",
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            "status": "unaffected"
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        "versionType": "semver"
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        "version": "3.15.0",
        "lessThanOrEqual": "3.15.20",
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          {
            "at": "3.15.21",
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        "status": "affected",
        "version": "3.20.0",
        "lessThan": "3.20.1",
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            "at": "3.20.1",
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        "versionType": "semver"
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  }
]