CVE-2026-35577
Apollographql Apollo Mcp Server ≤ 1.7.0
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:NSummary
CVE-2026-35577 is a medium-severity Origin Validation Error (CWE-346) vulnerability in Apollographql Apollo Mcp Server. Its CVSS base score is 6.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique DHCP Spoofing (T1557.003); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-35577 is a vulnerability in Apollo MCP Server, a Model Context Protocol server that exposes GraphQL operations as MCP tools. Prior to version 1.7.0, the server failed to validate the Host header on incoming HTTP requests when using StreamableHTTP transport. This issue, linked to CWE-346, carries a CVSS score of 6.8 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N) and was published on 2026-04-09.
Attackers can exploit this vulnerability through DNS rebinding techniques from a malicious website visited by a user running the server locally on localhost without authentication or network controls. This bypasses same-origin policy restrictions, enabling the attacker's site to issue requests to the local MCP server on the user's behalf. Successful exploitation allows invocation of exposed tools or access to resources, though it requires user interaction and is limited to StreamableHTTP transport modes.
The vulnerability is addressed in Apollo MCP Server version 1.7.0. It does not impact stdio transport, and risks are mitigated by authentication, network-level access controls, or non-localhost bindings. Details are available in the GitHub security advisory (GHSA-wqrj-vp8w-f8vh) and related pull requests (#602, #635).
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21061
Vulnerability Data
Apollo MCP Server is a Model Context Protocol server that exposes GraphQL operations as MCP tools. Prior to version 1.7.0, the Apollo MCP Server did not validate the Host header on incoming HTTP requests when using StreamableHTTP transport. In configurations…
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where an HTTP-based MCP server is run on localhost without additional authentication or network-level controls, this could potentially allow a malicious website—visited by a user running the server locally—to use DNS rebinding techniques to bypass same-origin policy restrictions and issue requests to the local MCP server. If successfully exploited, this could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the local user. This issue is limited to HTTP-based transport modes (StreamableHTTP). It does not affect servers using stdio transport. The practical risk is further reduced in deployments that use authentication, network-level access controls, or are not bound to localhost. This vulnerability is fixed in 1.7.0.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp, model context protocol
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 3 hardening rules · 1 OS baseline
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Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.
Device identification and authentication mandates verifying the source before establishing connections.
Session authenticity mechanisms require validation that communications originate from the expected party.
Boundary protection at interfaces enforces checks on the origin of incoming communications.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Authentication directly verifies the source of users/services/hardware, mitigating origin validation failures.
Verifying identity assertions enforces origin validation for conveyed claims.
Documenting authorized flows supports origin validation by defining expected sources.
Protecting networks from unauthorized access requires origin checks on communication sources.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Network security controls enforce origin validation at network boundaries.
Security of network services includes validating the authenticity of service endpoints.
Network segregation reduces exposure but does not directly validate origins.
Application security requirements explicitly call for origin validation of inputs and communications.
Secure architecture principles encourage origin checks but do not mandate them.
Secure coding practices include implementing proper origin validation to prevent spoofing.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (3 rules)
- V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-346
- V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-346
- V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-346