CVE-2026-109527 affects selected HTTP transport and OAuth parsing routes, not stdio use. The advisory reports a 4 MiB rejection limit in corrected versions. Direct custom transport implementations may need their own bound; no actual campaign was established. A request-size check performed after consuming an entire body does not bound peak allocation.…
Inspect the ClaimsCase · DiggingBeagle record
Python MCP SDK buffered unbounded HTTP request bodies before the size check
An SDK-level denial-of-service weakness was corrected with a consistent request-body limit in supported builds.
Scope
Research claim attributed to the cited report, with limitations from intake DB-RADAR-CP7-CP7A-056.
Assessment profile
Assessment method- Setting
- research demonstration
- Exploitation
- demonstrated
- Evidence
- Grade C
- Remediation
- fixed reported
- AI role
- AGAINST AI
Basis and provenance
The advisory describes parser-level buffering before request limits. A four-MiB rejection bound is reported for corrected supported HTTP paths; stdio is outside the claimed affected route. Assessment uses the pinned Claims and source identities; public primary pages were not independently retrievable during this run. Impact remains unrated because field consequence or a comparable scoring rubric is not established.
Assessed Oct 15, 2026 using diggingbeagle.assessment/1.
Evidence basis: CLM-CP7A-MCP-HTTP-BODIES · Python MCP SDK oversized HTTP and OAuth request buffering CVE-2026-109527 — original research or disclosure
At a glance
Independent reproduction or full primary-document access in this research run was not achieved. Real-world incidence and broader model or deployment generalization are not established unless specifically stated.
Limits and uncertaintyFull account
CVE-2026-109527 affects selected HTTP transport and OAuth parsing routes, not stdio use. The advisory reports a 4 MiB rejection limit in corrected versions. Direct custom transport implementations may need their own bound; no actual campaign was established.
A request-size check performed after consuming an entire body does not bound peak allocation. Custom MCP deployments that bypass the SDK-provided HTTP paths must be tested at their own ingress layer.
Claims & evidence
CLM-CP7A-MCP-HTTP-BODIESThe cited authors or maintainers report the following bounded finding: An SDK-level denial-of-service weakness was corrected with a consistent request-body limit in supported builds.supported
Basis: reported finding
- supportsPython MCP SDK oversized HTTP and OAuth request buffering CVE-2026-109527 — original research or disclosureprimary disclosure
Original primary document, reported finding and evaluation context; checkpoint DB-RADAR-CP7-CP7A-056
Unknowns and contradictions
- Independent reproduction or full primary-document access in this research run was not achieved.
- Real-world incidence and broader model or deployment generalization are not established unless specifically stated.
Sources and citation
Material revision history
- Oct 15, 2026 · Canonical change recorded · new in release · revision 150