Markdown Preview Enhanced before 0.8.28 parses Bitfield fenced code blocks with interpretJS(), which evaluates the block content as code via vm.runInNewContext(), allowing arbitrary code execution. A crafted markdown document containing a malicious bitfield code block executes attacker-controlled code on the server side when the document is rendered or exported. Fixed in 0.8.28 by parsing bitfield register definitions with JSON5.parse(), since they are purely data.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-94"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49493.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "0.8.28"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"original_tag": "0.8.28",
"range": [
{
"fixed": "dcd80281c986293b93d9f1af34ced64dcb230c77"
}
],
"source": "REFERENCES_TAG"
},
{
"range": [
{
"introduced": "0"
},
{
"fixed": "0.8.28"
}
],
"source": "DESCRIPTION"
}
]
}