CVE-2026-102503: Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.4%
EPSS score, percentile 37.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.
CISA's SSVC assessment in the CVE record lists exploitation as poc.
- How severe?
- 9.3 Critical
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- from 0.1.0-alpha.1 to before 0.1.0-alpha.3
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
What to do
Advisories and patches
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 0.1.0-alpha.1 to before 0.1.0-alpha.3 |
Versions not listed are: unaffected.
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
About this vulnerability
Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http ingress server (StartIngressServer in cmd/sam-node/node.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.2 allow an unauthenticated remote libp2p peer to bypass Biscuit capability policy enforcement and invoke arbitrary registered backend services (including…
Summary: CVE record, as of .
- CISA has not added CVE-2026-102503 to its Known Exploited Vulnerabilities (KEV) catalog, as of 28 Oct 2026.
- The CVE record was published on 19 Oct 2026.
- The CVE record carries a CVSS v4.0 base score of 9.3 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 37.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation poc, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
Missing Authentication for Critical Function (CWE-306) and Missing Authorization (CWE-862) in the /libp2p-http ingress server (StartIngressServer in cmd/sam-node/node.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.2 allow an unauthenticated remote libp2p peer to bypass Biscuit capability policy enforcement and invoke arbitrary registered backend services (including command/stdio-backed MCP servers, A2A, and inference endpoints). While the MCP protocol stream handler enforces WithBiscuitAuth and Authorize checks, the parallel /libp2p-http ingress routes requests directly to backend service handlers without verifying a Biscuit token or mesh enrollment. Users should upgrade to version 0.1.0-alpha.3 or later.
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
Weakness
Attack patterns (CAPEC)
- CAPEC-115: Authentication Bypass
- CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published |
Known exploited Google vulnerabilities
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- CVE-2026-58704: Google Pixel Improper Authorization Vulnerability
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- CVE-2026-85046: Google Chromium V8 Type Confusion Vulnerability
- CVE-2026-11645: Google Chromium V8 Out-of-Bounds Read and Write Vulnerability