High severity · published Oct 21, 2026
CVE-2026-103090
Unauthenticated Biscuit Credential Disclosure via GET /enroll/status in Google OSS Agent Mesh (SAM)
New
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
Missing Authentication for Critical Function (CWE-306) and Insufficiently Protected Credentials (CWE-522) in the control plane enrollment status handler (HandleEnrollStatus at GET /enroll/status in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow an unauthenticated remote attacker to retrieve an approved bootstrap-enrolled peer's signed Biscuit identity token by supplying a peer_id obtainable from the unauthenticated GET /info endpoint. A related flaw in POST /enroll allowed any bootstrap-token holder to re-fetch another peer's credential. An attacker can replay the disclosed Biscuit token as a bearer credential on /policies to read mesh authorization policies and on /routers/lease to overwrite advertised router multiaddrs. Users should upgrade to version 0.1.0-alpha.9 or later, which requires cryptographic proof of possession of the enrollment private key on credential-releasing endpoints, enforces rate limiting, and validates router lease addresses.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SA
SAM · Google
0.1.0-alpha.1 before 0.1.0-alpha.9 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103090
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103090
github.com
https://github.com/google/sam/releases/tag/v0.1.0-alpha.9
github.com
https://github.com/google/sam/security/advisories/GHSA-hp3x-79wr-rx66
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Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)
9.3
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Missing Authentication on /libp2p-http Ingress in Google OSS Agent Mesh (SAM)
