CVE-2026-33252
Fixed in a distro release EPSS <1%CVSS 7.1
The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.1, the Go SDK's Streamable HTTP transport accepted browser-generated cross-site `POST` requests without validating the `Origin` header and without requiring `Content-Type: application/json`. In deployments without Authorization, especially stateless or sessionless configurations, this allows an arbitrary website to send MCP requests to a local server and potentially trigger tool execution. Version 1.4.1 contains a patch for the issue.
Products: modelcontextprotocol go-sdk
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/modelcontextprotocol/go-sdk | 1.4.1 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | datadog-cluster-agent-7.75 | no fix |
| Chainguard | datadog-cluster-agent-7.76 | 7.76.3-r4 |
| Chainguard | datadog-cluster-agent-fips-7.75 | no fix |
| Chainguard | datadog-cluster-agent-fips-7.76 | 7.76.3-r4 |
| Chainguard | ferretdb | 2.7.0-r10 |
| Chainguard | flux-operator-mcp | 0.45.0-r3 |
| Chainguard | flux-operator-mcp-fips | 0.45.0-r2 |
| Chainguard | gitlab-workhorse-ce-18.6 | no fix |
| Chainguard | gitlab-workhorse-ce-18.7 | no fix |
| Chainguard | gitlab-workhorse-ce-18.8 | 18.8.7-r1 |
| Chainguard | gitlab-workhorse-ce-18.9 | 18.9.3-r0 |
| Chainguard | gitlab-workhorse-ce-fips-18.6 | no fix |
| Chainguard | gitlab-workhorse-ce-fips-18.7 | no fix |
| Chainguard | gitlab-workhorse-ce-fips-18.8 | 18.8.7-r1 |
| Chainguard | gitlab-workhorse-ce-fips-18.9 | 18.9.3-r1 |
| Chainguard | glab | 1.90.0-r0 |
| Chainguard | jaeger-2-all-in-one | 2.16.0-r3 |
| Chainguard | jaeger-2-collector | 2.16.0-r3 |
| Chainguard | jaeger-2-fips-all-in-one | 2.16.0-r2 |
| Chainguard | jaeger-2-fips-collector | 2.16.0-r2 |
| Chainguard | jaeger-2-fips-ingester | 2.16.0-r2 |
| Chainguard | jaeger-2-fips-jaeger | 2.16.0-r2 |
| Chainguard | jaeger-2-fips-query | 2.16.0-r2 |
| Chainguard | jaeger-2-ingester | 2.16.0-r3 |
| Chainguard | jaeger-2-jaeger | 2.16.0-r3 |
| Chainguard | jaeger-2-query | 2.16.0-r3 |
| Chainguard | livekit-cli | 2.16.0-r3 |
| Chainguard | opencost | 1.119.2-r7 |
| Chainguard | opencost-fips | 1.119.2-r6 |
| Chainguard | osv-scanner | 2.3.3-r7 |
| Wolfi | datadog-cluster-agent-7.75 | no fix |
| Wolfi | datadog-cluster-agent-7.76 | 7.76.3-r4 |
| Wolfi | ferretdb | 2.7.0-r10 |
| Wolfi | glab | 1.90.0-r0 |
| Wolfi | jaeger-2-all-in-one | 2.16.0-r3 |
| Wolfi | jaeger-2-collector | 2.16.0-r3 |
| Wolfi | jaeger-2-ingester | 2.16.0-r3 |
| Wolfi | jaeger-2-jaeger | 2.16.0-r3 |
| Wolfi | jaeger-2-query | 2.16.0-r3 |
| Wolfi | opencost | 1.119.2-r7 |
| Wolfi | osv-scanner | 2.3.3-r7 |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260326T203309-150000.1.155.2 |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 |