{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-53428",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-53428",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-06-29T18:52:36.199Z",
    "updatedAt": "2026-06-30T04:38:36.755Z",
    "importedAt": "2026-10-24T01:58:20.586Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "Unbounded memory allocation in highlight_lines range expansion in mdex",
      "summary": "Memory Allocation with Excessive Size Value vulnerability in leandrocp mdex allows an unauthenticated attacker to cause a denial of service through unbounded memory allocation.\n\ncomrak_nif::lumis_adapter::LumisAdapter::parse_highlight_lines in native/comrak_nif/src/lumis_adapter.rs eagerly expands a user-controlled inclusive line range from a fenced code block's highlight_lines decorator into a Vec<usize>, pushing one element per integer in the range with no upper bound on the range size. An attacker who can supply Markdown that an application renders with MDEx.to_html/2 (for example a comment, chat message, or wiki page) can embed a code block whose info string is rust highlight_lines=\"1-100000000\", forcing the native adapter to allocate roughly 8 bytes per line in the range.\n\nA payload that differs by only a few bytes can therefore allocate hundreds of megabytes, and a sufficiently large range (for example 1-2000000000) exhausts host memory and aborts the BEAM, denying service to every user of the rendering process. The per-line write loop additionally tests membership with a linear scan over the same vector, degrading rendering to a quadratic cost even for ranges that do not immediately exhaust memory.\n\nThe vulnerable native code originally shipped inside mdex (in native/comrak_nif/src/lumis_adapter.rs) and was later extracted into the separate mdex_native package (native/mdex_native_nif/src/lumis_adapter.rs), where it remains unpatched.\n\nThis issue affects mdex from 0.11.0 before 0.12.3, and mdex_native from 0.1.0 before 0.2.3.",
      "affected": [
        {
          "vendor": "leandrocp",
          "product": "mdex",
          "packageName": "mdex",
          "collectionURL": "https://repo.hex.pm",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0.11.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "0.12.3"
            }
          ]
        },
        {
          "vendor": "leandrocp",
          "product": "mdex",
          "packageName": "leandrocp/mdex",
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "a8407611715d1ead35fbcba79c72cef1b7df387b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6ed94d905f97af188323f042698ae841c02293b4"
            }
          ]
        },
        {
          "vendor": "leandrocp",
          "product": "mdex_native",
          "packageName": "mdex_native",
          "collectionURL": "https://repo.hex.pm",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0.1.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "0.2.3"
            }
          ]
        },
        {
          "vendor": "leandrocp",
          "product": "mdex_native",
          "packageName": "leandrocp/mdex_native",
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "956528c5e31746253347029e810a969ab916fd27",
              "status": "affected",
              "versionType": "git",
              "lessThan": "798a363b4339f6f7162ec8437c4c9f9b5ae6fbf3"
            }
          ]
        }
      ]
    }
  }
}