VDB
CVE-2026-59951
CVE-2026-59951
PUBLISHED
CVSS 6.900000095367432 MEDIUM
MCP Python SDK: Unbounded Session Accumulation in StreamableHTTP Transport Enables Resource Exhaustion
EPSS 0.46% · 39.7th percentile
Risk Scores
CVSS 4.0
6.900000095367432
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS Score
0.46%
39.7th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| PyPI | mcp | 1.8.0, 2.0.0 |
| modelcontextprotocol | python-sdk | 2.0.0, 1.8.0 |
| wolfi | semgrep | 0 |
| chainguard | open-webui | 0 |
| chainguard | nemo-gym | 0 |
| wolfi | open-webui | 0 |
| chainguard | semgrep | 0 |
| chainguard | nemo-rl-cuda-13.0 | 0 |
Timeline
- Oct 14, 2026 Coalition ESS Score
- Oct 14, 2026 CVE Published
- Oct 15, 2026 CVE Updated
- Oct 15, 2026 EPSS Score
- Oct 19, 2026 EPSS Score
- Oct 21, 2026 EPSS Score
- Oct 24, 2026 EPSS Score
- Oct 25, 2026 EPSS Score
- Oct 29, 2026 EPSS Score
- Oct 30, 2026 Security Advisory
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-59951 advisory
- https://github.com/advisories/GHSA-84m7-p3x7-pcfv advisory
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-84m7-p3x7-pcfv url
- https://github.com/modelcontextprotocol/python-sdk/pull/3395 patch
- https://github.com/modelcontextprotocol/python-sdk/pull/3426 patch
- https://github.com/modelcontextprotocol/python-sdk/commit/92120b4b0f50385af096592d7cee932fc1d994e7 patch
- https://github.com/modelcontextprotocol/python-sdk/commit/d2290ca3434731b68ea3e2270bc06a6e6575931b patch
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0 url
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0 url