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SCA: security update for github.com/modelcontextprotocol/go-sdk (GHSA-wvj2-96wp-fq3f)

high Tenable Self-Hosted Container Security Plugin ID 438126

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - The Go MCP SDK used Go's standard encoding/json.Unmarshal for JSON-RPC and MCP protocol message parsing in
 versions prior to 1.3.1. Go's standard library performs case-insensitive matching of JSON keys to struct
 field tags — a field tagged json:"method" would also match "Method", "METHOD", etc. This violated the
 JSON-RPC 2.0 specification, which defines exact field names. A malicious MCP peer may have been able to
 send protocol messages with non-standard field casing that the SDK would silently accept. This had the
 potential for bypassing intermediary inspection and coss-implementation inconsistency. Go's standard JSON
 unmarshaling was replaced with a case-sensitive decoder in commit 7b8d81c. Users are advised to update to
 v1.3.1 to resolve this issue. (CVE-2026-27896)

See Also

https://github.com/advisories/GHSA-wvj2-96wp-fq3f

Plugin Details

Severity: High

ID: 438126

Version: Revision 1.10

Type: Local

Family: SCA Checks

Published: 3/3/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.72

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

CVSS Score Source: CVE-2026-27896

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 7

Threat Score: 2.7

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 2/26/2026

Vulnerability Publication Date: 2/26/2026

Reference Information

CVE: CVE-2026-27896