{"id":"CVE-2026-76238","aliases":["GHSA-6gqw-jqv7-v88m"],"url":"https://o3.security/vulnerability/CVE-2026-76238","summary":"stigmem before 0.9.0a12 Cross-Tenant BOLA via decay sweep","details":"### Summary\nOn a multi-tenant stigmem node, a caller holding a `write` credential for **one** tenant can run a decay sweep that acts on **every** tenant's facts. The candidate-selection queries in `lifecycle/decay.py` (`_select_ttl_candidates`, `_select_confidence_candidates`) carried no `tenant_id` predicate, and the caller's tenant was not threaded into the sweep or its async worker (`run_decay_sweep` / `_decay_job_worker`), reached via `POST /v1/decay/sweep`.\n\n### Impact\nA sweep with `ttl_seconds=0` expires **all tenants'** facts — cross-tenant data destruction (integrity and availability). A `dry_run` sweep returns a global candidate count, acting as a cross-tenant existence/volume **oracle** (information disclosure).\n\n### Affected configurations\nThis is a cross-**tenant** break. It is exploitable **only** on deployments running the opt-in `stigmem-plugin-multi-tenant` (multiple tenants on one node). A default single-tenant node has only `tenant=\"default\"` — there is no second tenant to cross — so it is **not exploitable** on default deployments. The rating is HIGH for the multi-tenant deployments the plugin exists to isolate.\n\n### Patches\nFixed in `0.9.0a12` (PR #728): `identity.tenant_id` is threaded into `run_decay_sweep` and `_decay_job_worker`, and `AND tenant_id = ?` was added to the candidate selectors and the graph-sync. A tenant-B sweep now leaves tenant-A facts untouched, and `dry_run` counts only the caller's tenant. The `check_fact_query_tenant_scope.py` CI guard was extended to scan `lifecycle/` so this class cannot silently regress.\n\n### Workarounds\nNone other than upgrading to `0.9.0a12`. Single-tenant deployments are unaffected.","published":"2026-08-19T14:02:16.612Z","modified":"2026-10-28T02:30:37.206834897Z","cvss":null,"epss":{"score":0.00265,"percentile":0.18615,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"stigmem-node","fixedVersion":"0.9.0a12"}],"fix":{"url":"https://github.com/eidetic-labs/stigmem/pull/728","label":"eidetic-labs/stigmem#728"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/76xxx/CVE-2026-76238.json"},{"type":"ADVISORY","url":"https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-6gqw-jqv7-v88m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76238"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/stigmem-before-0a12-cross-tenant-bola-via-decay-sweep"},{"type":"WEB","url":"https://github.com/eidetic-labs/stigmem/pull/728"},{"type":"PACKAGE","url":"https://github.com/eidetic-labs/stigmem"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:37.206834897Z"}}