Improper Handling of Case Sensitivity Affecting gitlab-workhorse-ce-fips-18.7 package, versions <18.7.5-r1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

Social Trends
EPSS
0.26% (17th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-GITLABWORKHORSECEFIPS187-15423738
  • published5 Mar 2026
  • disclosed26 Feb 2026

Introduced: 26 Feb 2026

CVE-2026-27896  (opens in a new tab)
CWE-178  (opens in a new tab)
CWE-436  (opens in a new tab)

How to fix?

Upgrade Chainguard gitlab-workhorse-ce-fips-18.7 to version 18.7.5-r1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream gitlab-workhorse-ce-fips-18.7 package and not the gitlab-workhorse-ce-fips-18.7 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1