CVE-2026-49493
Published: 05 June 2026
Summary
CVE-2026-49493 is a high-severity Code Injection (CWE-94) vulnerability. Its CVSS base score is 8.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 24.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-34869
Vulnerability details
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct RCE via JS code injection in server-side markdown rendering (vm.runInNewContext) maps to T1190 (public app exploit) and T1059.007 (JS interpreter abuse).
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.
Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.
Validates inputs used in dynamic code generation to block injected directives.
Directly prevents execution of attacker-supplied code written into data memory regions.