CVE intelligence and bounded remediation
CVE-2025-6515 — The MCP SSE endpoint in oatpp-mcp returns an instance pointer as the session ID, which is not unique nor cryptographically secure
Medium
CVSS 6.8
The MCP SSE endpoint in oatpp-mcp returns an instance pointer as the session ID, which is not unique nor cryptographically secure. This allows network attackers with access to the oatpp-mcp server to guess future session IDs and hijack legitimate client MCP sessions, returning malicious responses from the oatpp-mcp server.
- Severity
- Medium
- CVSS
- 6.8 (3.1)
- Published
- 2025-10-20
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-330
Affected products
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Matched remediation archetype
Cryptography, certificate, signature, and channel validation
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Inventory affected algorithms, key uses, trust stores, certificate validation settings, random sources, and plaintext channels across clients and services.
- Determine which secrets, identities, signatures, or data protections depend on the affected primitive or validation path.
- Check debug, compatibility, fallback, and hostname or audience override settings in build and runtime configuration.
Remediate safely
- Use a maintained platform cryptographic API with approved algorithms, modes, parameters, randomness, and full peer identity validation.
- Remove insecure fallback and validation bypasses; separate keys by purpose and load them from managed secret storage.
- Plan rotation or reissuance for affected keys, certificates, tokens, hashes, or ciphertext and document compatibility sequencing.
Authoritative sources
Complete CVE record and remediation plan
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