CVE-2026-103091
Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)
No known exploitation. EPSS puts it in the 51st percentile. Fixed in 0.1.0-alpha.9.
What to do
Find your product and version, then upgrade to the build on the right.
- Google SAMAffected: ≥ 0.1.0-alpha.1, < 0.1.0-alpha.9Upgrade to: 0.1.0-alpha.9Stated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
Missing Authorization (CWE-862) and Initialization of a Resource with an Insecure Default (CWE-1188) in the MCP proxy (HandleStreamPassThrough in mcp_service.go) and OIDC registration flow (GET /info and POST /register in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes. Because GET /info publicly discloses OIDC configuration, POST /register auto-enrolls any valid OIDC token holder without claim filtering or ban checks, and the default policy binds sam:system:authenticated to wildcard services and targets, an attacker can obtain a mesh credential with full read, write, and execution access on backend services. Users should upgrade to version 0.1.0-alpha.9 or later, which enforces a fail-closed default policy, explicit policy-binding requirements on enrollment, and ban checks.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 51st percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
6 events over 0 days, from the signal feeds we watch.
- Publishedweakness classified, att&ck mapped, record updated, record updated, record updated
Affected products
Technical detail
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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