CVE-2026-108714

MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocket

CVSS score

8.7

EPSS probability

—

Risk score

0.9

Published

11 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

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

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

MCP Kotlin SDK Memory Exhaustion Vulnerability

Sources read

Source agreement

0/2

Evidence confidence

%44

Short explanation

MCP Kotlin SDK through version 0.15.0 contains an uncontrolled memory allocation vulnerability because Application.mcpWebSocket installs Ktor WebSockets without a maxFrameSize limit, allowing remote clients to exhaust server memory.

Why does it matter?

Remote attackers can send small frame headers declaring large payloads, forcing massive heap allocations and causing a denial of service.

What should be done?

Follow vendor advisories
Apply available updates

Note on uncertainty

2 alanda kaynak uyuşmazlığı var. DayBreach bu değerleri saklamadı; kaynak karşılaştırması aşağıda gösteriliyor.

Chain of evidence and sources2 verified claims

MCP Kotlin SDK 0.15.0 ve önceki sürümler, Application.mcpWebSocket bileşeninde maxFrameSize sınırının olmaması nedeniyle denetimsiz bellek tahsisine açıktır.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Saldırganlar 2 GiB civarında yük bildiren küçük çerçeve başlıkları göndererek sunucu belleğini tüketebilir ve hizmet kesintisine yol açabilir.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Show the technical text from the sources

MCP Kotlin SDK through 0.15.0 contains an uncontrolled memory allocation vulnerability that allows remote clients to exhaust server memory because Application.mcpWebSocket installs Ktor WebSockets without a maxFrameSize limit. Attackers can send small frame headers declaring payloads near 2 GiB over one or a few connections, forcing huge heap allocations and causing denial of service.

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CWE: CWE-770

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-108714 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	modelcontextprotocol	kotlin-sdk	View

Total affected vendors: 1|Products: 1

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.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
8.7	CVSS V4_0	HIGH	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	CVE CNA
8.7	CVSS V40	HIGH	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD
7.5	CVSS V3_1	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CVE CNA
7.5	CVSS V31	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD

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-2026-108714 is associated with the following CWEs:

CWE-770: Allocation of Resources Without Limits or Throttling

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-2026-108714 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

https://hackmd.io/@haind/mcp-kotlin-sdk-websocket-frame-allocation-dosvendor-advisory https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/WebSocketMcpKtorServerExtensions.kt#L41-L63vendor-advisory https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/WebSocketMcpTransport.kt#L60-L85vendor-advisory https://github.com/modelcontextprotocol/kotlin-sdkvendor-advisory VulnCheck Advisory: MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocketvendor-advisory

CVSS Vector Radar Chart

8.7 / 10

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionNone required

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)None

Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

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

Follow the vendor

modelcontextprotocol

Weakness Type (CWE & CAPEC)

CWE-770

Similar Vulnerabilities

7.5

CVE-2026-63128

RMCP: Unauthenticated permanent session-table leak in rmcp Streamable HTTP server transport leads to remote denial-of-service

VendormodelcontextprotocolProductrust-sdk+2 etkilenen

Patch status unknownEPSS %125 d ago

6.9

CVE-2026-53965

MCP PHP SDK: Unbounded SSE buffer in HttpTransport enables client-side denial of service

VendormodelcontextprotocolProductphp-sdk+2 etkilenen

Patch status unknownEPSS %11 mo ago

6.8

CVE-2026-64684

RMCP: Custom HTTP headers leak to cross-origin redirect targets

VendormodelcontextprotocolProductrust-sdk+2 etkilenen

Patch status unknownEPSS %125 d ago

7.0

CVE-2026-27896

MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity

VendormodelcontextprotocolProductgo-sdk+2 etkilenen

Patch verifiedEPSS %07 mo ago

6.9

CVE-2026-104120

modelcontextprotocol mcp-server-fetch/mcp-server-everything Fetch Tool server.py fetch_url server-side request forgery

VendormodelcontextprotocolProductmcp-server-fetch+1 etkilenen

Patch verifiedEPSS %09 d ago

8.2

CVE-2026-63127

RMCP: Missing Resource Field Validation in OAuth Protected Resource Metadata Discovery

VendormodelcontextprotocolProductrust-sdk+2 etkilenen

Patch status unknownEPSS %025 d ago

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free key Documentation

curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-108714"

MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocket

Impact on My Inventory

Vulnerability description

DayBreach AI Explanation

Short explanation

What should be done?

IMPACT: Affected Products and Software

Affected Products

RED HAT CSAF/VEX: Product Impact Check

SCORING: CVSS from Multiple Sources

CVSS Scores

Patch and Remediation Guide

Solution & Remediation Advisory

Public exploit and active exploitation status

Verified exploit intelligence

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

Common Attack Pattern Enumeration and Classification (CAPEC)

Attack Vector and Accessibility

Official Sources and Advisories

CVSS Vector Radar Chart

Vulnerability Scoring Details

Weakness Type (CWE & CAPEC)

Similar Vulnerabilities

RMCP: Unauthenticated permanent session-table leak in rmcp Streamable HTTP server transport leads to remote denial-of-service

MCP PHP SDK: Unbounded SSE buffer in HttpTransport enables client-side denial of service

RMCP: Custom HTTP headers leak to cross-origin redirect targets

MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity

modelcontextprotocol mcp-server-fetch/mcp-server-everything Fetch Tool server.py fetch_url server-side request forgery

RMCP: Missing Resource Field Validation in OAuth Protected Resource Metadata Discovery

Get this vulnerability through the API

DayBreach

Glossary & Reference

Directories & Feeds

RSS & Integration