CVE intelligence and bounded remediation

CVE-2022-23631 — superjson is a program to allow JavaScript expressions to be serialized to a superset of JSON

Critical CVSS 9.8

superjson is a program to allow JavaScript expressions to be serialized to a superset of JSON. In versions prior to 1.8.1 superjson allows input to run arbitrary code on any server using superjson input without prior authentication or knowledge. The only requirement is that the server implements at least one endpoint which uses superjson during request processing. This has been patched in superjson 1.8.1. Users are advised to update. There are no known workarounds for this issue.

Severity
Critical
CVSS
9.8 (3.1)
Published
2022-02-09
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-94, CWE-1321

Affected products

  • blitzjs / blitz
  • blitzjs / superjson

Matched remediation archetype

Command, code, expression, and template injection

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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