CVE-2026-76245

stigmem-node contains an insecure default configuration that allows federation traffic to traverse networks without mTLS protection when non-loopback endpoints are enabled. Operators who explicitly disabled mTLS while binding federation to non-loopback addresses expose federation traffic to cleartext interception and man-in-the-middle attacks.

stigmem-node 0.9.0a1 accepts federation peer key material during peer registration without a separate administrator out-of-band fingerprint approval step. On nodes that accept federation peer registration over a network where initial registration can be intercepted or misdirected, an attacker can register a malicious peer and gain access to or tamper with federation traffic. Fixed in 0.9.0a2, which introduces a pending approval flow requiring administrator fingerprint verification before peer tokens are accepted.

stigmem-node 0.9.0a1 allows plugin signature enforcement to be disabled via a single configuration flag without a second explicit acknowledgment. If that setting is carried into an environment where plugin directories are writable by less-trusted users, unsigned (potentially malicious) plugin code could be loaded and executed, resulting in arbitrary code execution. Fixed in 0.9.0a2.

stigmem-node 0.9.0a1 interpolates Postgres backend schema identifiers into SQL strings without defensive quoting. In the affected code path the schema value is operator-controlled, but the unsafe pattern could allow SQL injection if a schema name were derived from tenant, request, or user input. Fixed in 0.9.0a2.

stigmem-node before 0.9.0a12 contains a broken object level authorization (cross-tenant BOLA) vulnerability in the quarantine review endpoints. On multi-tenant deployments running the opt-in stigmem-plugin-multi-tenant, the list/count queries and _get_quarantined_fact in routes/quarantine.py lacked a tenant_id predicate and the garden lookup was not tenant-scoped, allowing a tenant administrator with only a plain tenant write capability to list, read, and admit or reject quarantined facts belonging to other tenants via the /v1/quarantine endpoints. Default single-tenant deployments are not affected.

stigmem-node before 0.9.0a12 contains a cross-tenant broken object level authorization (BOLA) flaw in the RTBF (right-to-be-forgotten) tombstone mechanism. issue_tombstone defaulted the tenant to "default" instead of the caller's tenant, allowing deletion records to be written to the wrong tenant, and the read-suppression path (_get_tombstone_filter and the tombstone scope cache) lacked a tenant_id predicate, so tombstone suppression was applied tenant-blind across fact queries and provenance reads. As a result, a tenant's deletion could be attributed to the wrong tenant and tombstone suppression could either hide facts belonging to other tenants or fail to hide facts within the correct tenant, undermining data isolation and RTBF guarantees. The issue is exploitable only on multi-tenant deployments running the opt-in stigmem-plugin-multi-tenant; single-tenant deployments are unaffected. Fixed in 0.9.0a12.