CVE-2026-34237 (GCVE-0-2026-34237)
Vulnerability from cvelistv5 – Published: 2026-03-31 15:40 – Updated: 2026-06-09 18:39
VLAI
EPSS
VEX
Title
MCP Java SDK has a Hardcoded Wildcard CORS (Access-Control-Allow-Origin: *)
Summary
MCP Java SDK is the official Java SDK for Model Context Protocol servers and clients. Prior to versions 0.83.0, 1.0.1, and 1.1.1, there is a hardcoded wildcard CORS vulnerability. This issue has been patched in versions 0.83.0, 1.0.1, and 1.1.1.
Severity
6.1 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-31 18:50 UTC
CWE
- CWE-942 - Permissive Cross-domain Policy with Untrusted Domains
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/modelcontextprotocol/java-sdk/… | x_refsource_CONFIRM |
| https://github.com/modelcontextprotocol/java-sdk/… | x_refsource_MISC |
| https://github.com/modelcontextprotocol/java-sdk/… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| modelcontextprotocol | java-sdk |
Affected:
>= 1.0.0, < 1.0.1
Affected: >= 1.1.0, < 1.1.1 Affected: < 0.18.3 |
guessed |
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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