CVE-2026-108859

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Source
https://cve.org/CVERecord?id=CVE-2026-108859
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-108859.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-108859
Published
2026-10-11T13:26:06Z
Modified
2026-10-13T10:48:07Z
Severity
  • 8.7 (High) CVSS_V4 - 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 CVSS Calculator
Summary
mcp-go through 1.2.1 Denial of Service via Unbounded POST Body Buffering
Details

mcp-go through 1.2.1 contains a denial of service vulnerability in StreamableHTTPServer.ServeHTTP that allows remote unauthenticated attackers to exhaust memory by sending oversized POST bodies. Attackers can send arbitrarily large or many concurrent POST requests, read fully via io.ReadAll before validation, to degrade or OOM-kill the server process.

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/108xxx/CVE-2026-108859.json"
}
References

Affected packages

Git / github.com/mark3labs/mcp-go

Affected ranges

Type
GIT
Repo
https://github.com/mark3labs/mcp-go
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
90d247ed8d45cbb7d71d9a95e112789b78760443
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "last_affected":  "1.2.1"
        },
        {
            "fixed":  "1.2.1"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

otel/v0.*
otel/v0.54.0
v0.*
v0.1.0
v0.1.1
v0.1.2
v0.1.3
v0.1.4
v0.1.5
v0.1.6
v0.10.0
v0.10.1
v0.10.2
v0.10.3
v0.11.0
v0.11.1
v0.11.2
v0.12.0
v0.13.0
v0.14.0
v0.14.1
v0.15.0
v0.16.0
v0.17.0
v0.18.0
v0.19.0
v0.2.0
v0.20.0
v0.20.1
v0.21.0
v0.21.1
v0.22.0
v0.23.0
v0.23.1
v0.24.0
v0.24.1
v0.25.0
v0.27.0
v0.27.1
v0.28.0
v0.29.0
v0.3.0
v0.30.0
v0.30.1
v0.31.0
v0.32.0
v0.33.0
v0.34.0
v0.35.0
v0.36.0
v0.37.0
v0.38.0
v0.39.0
v0.39.1
v0.4.0
v0.4.1
v0.40.0
v0.41.0
v0.41.1
v0.42.0
v0.42.0-beta.1
v0.42.0-beta.2
v0.42.0-beta.3
v0.43.0
v0.43.0-beta.1
v0.43.0-beta.2
v0.43.0-beta.3
v0.43.1
v0.43.2
v0.44.0
v0.44.0-beta.1
v0.44.0-beta.2
v0.44.0-beta.3
v0.44.1
v0.45.0
v0.46.0
v0.47.0
v0.47.1
v0.48.0
v0.49.0
v0.5.0
v0.5.1
v0.5.10
v0.5.2
v0.5.3
v0.5.4
v0.5.5
v0.5.6
v0.5.7
v0.5.8
v0.5.9
v0.50.0
v0.51.0
v0.52.0
v0.53.0
v0.54.0
v0.54.1
v0.55.0
v0.55.1
v0.56.0
v0.57.0
v0.58.0
v0.6.0
v0.7.0
v0.8.0
v0.8.1
v0.8.2
v0.8.3
v0.8.4
v0.8.5
v0.9.0
v1.*
v1.0.0
v1.0.0-beta.1
v1.1.0
v1.1.1
v1.2.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-108859.json"