Full Report
React security advisory (AV26-123)
Analysis Summary
# Vulnerability: Arbitrary Code Execution in next-mdx-remote Server-Side Rendering
## CVE Details
- **CVE ID:** *Information not explicitly provided in the summary text, assumed to be associated with HCSEC-2026-01.*
- **CVSS Score:** *Score not explicitly provided, severity assessment pending full advisory review.*
- **CWE:** *CWE not explicitly provided.*
## Affected Systems
- **Products:** next-mdx-remote (A component related to React server-side rendering)
- **Versions:** 4.3.0 to 5.0.0 (inclusive)
- **Configurations:** Systems utilizing next-mdx-remote for server-side rendering of untrusted MDX content.
## Vulnerability Description
HashiCorp disclosed a vulnerability concerning the server-side rendering (SSR) of untrusted MDX content within the next-mdx-remote package. This vulnerability may allow for arbitrary code execution when processing malicious input. (The specific technical mechanism, such as improper input sanitization or deserialization, would require reviewing HCSEC-2026-01.)
## Exploitation
- **Status:** *Status not explicitly provided; assumed to be disclosed but not confirmed as exploited in the wild based solely on this abstract.*
- **Complexity:** *Complexity not explicitly provided.*
- **Attack Vector:** *Attack Vector not explicitly provided.*
## Impact
- **Confidentiality:** *Impact level not explicitly provided.*
- **Integrity:** *Impact level not explicitly provided (likely high due to potential for Code Execution).*
- **Availability:** *Impact level not explicitly provided.*
## Remediation
### Patches
- **Update to fixed version:** Administrators should consult the linked HashiCorp advisory (HCSEC-2026-01) for the specific patched version that resolves the vulnerability for versions up to 5.0.0.
### Workarounds
- *No specific workarounds were listed in this advisory summary.* (Recommend limiting or validating all input processed by server-side rendering if immediate patching is not possible.)
## Detection
- **Indicators of compromise:** *Not specified in summary.*
- **Detection methods and tools:** Focus on monitoring SSR operations initiated by next-mdx-remote for unexpected process behavior or execution attempts coming from processed input paths.
## References
- **Vendor Advisories:**
- HashiCorp Advisory: hxxps://discuss.hashicorp.com/t/hcsec-2026-01-arbitrary-code-execution-in-react-server-side-rendering-of-untrusted-mdx-content/77155