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CVE-2026-116685

Model Context Protocol Python SDK: HTTP client transports followed cross-origin redirects carrying custom headers and bodies

CVSS score

5.9

EPSS probability

—

Risk score

0.6

Published

3 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

CVE-2026-116685: Model Context Protocol Python SDK Redirect Vulnerability

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

The Model Context Protocol Python SDK follows cross-origin redirects on certain HTTP client paths, potentially leaking custom credential headers and request bodies.

Why does it matter?

Sensitive credentials and request data can be forwarded to an untrusted redirect destination, leading to a confidentiality breach.

What should be done?

  • Follow vendor advisories to track Model Context Protocol Python SDK updates
  • Review redirect behaviors across affected client paths
Chain of evidence and sources2 verified claims

Model Context Protocol Python SDK, çapraz kökenli yönlendirmeler sırasında özel başlıkları ve gövdeleri aktarabilir.

S0 · daybreach-canonicalS1 · cvelist

Bu güvenlik açığı 1.8.0 sürümünden 1.30.0 ve 2.2.0 sürümlerine kadar olan aralığı etkilemektedir.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.8.0 until 1.30.0 and 2.2.0, streamable_http_client, streamablehttp_client, sse_client, ClientSessionGroup, OAuth, and create_mcp_http_client client paths enable follow_redirects and follow redirects to a different origin, forwarding caller-supplied custom credential headers and, for 307 or 308 responses, the request body. An attacker who can influence a trusted endpoint's redirect destination can receive that material. This issue is fixed in versions 1.30.0 and 2.2.0.

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE: CWE-200

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-116685 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1modelcontextprotocolpython-sdk View
2pypimcp View
3pypimcp View
Total affected vendors: 2|Products: 3

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
5.9CVSS V31MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NNVD
5.9CVSS V3_1MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCVE CNA
5.9CVSS 3.x—Vector not publishedGitHub Advisory
0.0CVSS 4.0—Vector not publishedGitHub Advisory

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-116685 is associated with the following CWEs:

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-116685 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-5h93-6whr-6q8jvendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/pull/3397vendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/pull/3448vendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/commit/2106335745563b2321b8c73fef2c12903d00aa6evendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/commit/c6762e821c527925f0b617db216d00fbd1d0bf99vendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0vendor-advisoryhttps://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0vendor-advisoryhttps://github.com/advisories/GHSA-5h93-6whr-6q8jvendor-advisory

CVSS Vector Radar Chart

5.9 / 10
Attack VectorNetworkComplexityHighPrivilegesNoneUser Interact.NoneConfidentialityHighIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)High
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

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Weakness Type (CWE & CAPEC)

CWE-200

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CVE-2026-116685 · Model Context Protocol Python SDK: HTTP…