GHSA-x26h-xmv8-gxf7: stigmem-node RTBF Tombstones Are Mis-attributed And Vulnerability

HIGH
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CWE-639
Published
Advisory Summary

GHSA-x26h-xmv8-gxf7 is a HIGH rtbf tombstones are mis-attributed and vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting stigmem-node libraries in the PyPI ecosystem. The issue involves rtbf tombstones are mis-attributed and suppress reads tenant-blind (cross-tenant bola). Remediation is available by upgrading affected packages to version 0.9.0a12.

GHSA-x26h-xmv8-gxf7 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-x26h-xmv8-gxf7
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product stigmem-node
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix GHSA-x26h-xmv8-gxf7

To remediate this vulnerability, upgrade all affected stigmem-node dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

stigmem-node fixed: 0.9.0a12 
pip install stigmem-node>=0.9.0a12
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show stigmem-node

How to Check if You Are Affected

To determine whether your Python environment is affected by GHSA-x26h-xmv8-gxf7, inspect your installed packages using pip:

pip show stigmem-node

Analyze the terminal output to locate any version of stigmem-node in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.9.0a12), your application is affected.

Note: The pip show stigmem-node command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In stigmem-node, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary On a multi-tenant stigmem node, RTBF (right-to-be-forgotten) tombstones were mis-scoped two ways. (1) `issue_tombstone` defaulted the tenant to `"default"` instead of the caller's tenant, so tombstones could be written to the wrong tenant. (2) The read-suppression path — `_get_tombstone_filter` (`routes/facts/common.py`) and the `_tombstone_scope_cache` (`lifecycle/tombstones.py`) — had no `tenant_id` predicate, so tombstone suppression was applied tenant-blind across fact queries and provenance. Reached via `/v1/tombstones` and the fact query/provenance read paths. ### Impact Cross-tenant integrity of the RTBF mechanism: a tenant's deletion request could be recorded against the wrong tenant, and tombstone suppression could hide — or fail to hide — facts across tenant boundaries, undermining both data-view correctness and RTBF guarantees. ### Affected configurations This 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. ### Patches Fixed in `0.9.0a12` (PR #728): `identity.tenant_id` is passed from `issue_tombstone` into `create_tombstone` (no more `"default"` fallback); `AND tenant_id = ?` was added to `_get_tombstone_filter` and `get_tombstone_status`; the suppression cache is re-keyed to include tenant; and all four read call sites thread the caller's tenant. A tenant-B tombstone now suppresses only tenant-B facts and is invisible to tenant-A reads. ### Workarounds None other than upgrading to `0.9.0a12`. Single-tenant deployments are unaffected.

GHSA-x26h-xmv8-gxf7 Affected stigmem-node Versions

1 component(s)
Fixed Versions:
0.9.0a12
Product / Package Ecosystem Affected Versions Fixed Version
stigmem-node
pypi/stigmem-node
PyPI
< 0.9.0a12
0.9.0a12

References

GitHub Advisory / Wiki ADVISORY
https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-x26h-xmv8-gxf7
stigmem-node Source Repository REPOSITORY
https://github.com/eidetic-labs/stigmem/pull/728
stigmem-node Source Repository REPOSITORY
https://github.com/eidetic-labs/stigmem

Frequently Asked Questions

What is GHSA-x26h-xmv8-gxf7?
GHSA-x26h-xmv8-gxf7 is a security vulnerability in stigmem-node involving RTBF tombstones are mis-attributed and suppress reads tenant-blind (cross-tenant BOLA) under CWE-639: Authorization Bypass Through User-Controlled Key.
Which stigmem-node versions are affected?
Affected versions include releases prior to 0.9.0a12 across affected packages: stigmem-node.
What version fixes GHSA-x26h-xmv8-gxf7?
Upgrading to 0.9.0a12 (or the latest patched release for your respective branch) resolves the vulnerability.
Is stigmem-node affected?
Yes, stigmem-node is affected in releases prior to 0.9.0a12. Upgrade your dependency to 0.9.0a12 or later.
What CWE is associated with GHSA-x26h-xmv8-gxf7?
GHSA-x26h-xmv8-gxf7 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check PyPI dependencies for GHSA-x26h-xmv8-gxf7?
Run the dependency tree command: 'pip show stigmem-node'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x26h-xmv8-gxf7",
  "modified" : "2026-06-19T21:42:57Z",
  "published" : "2026-06-19T21:42:57Z",
  "aliases" : [ ],
  "summary" : "stigmem-node: RTBF tombstones are mis-attributed and suppress reads tenant-blind (cross-tenant BOLA)",
  "details" : "### Summary\nOn a multi-tenant stigmem node, RTBF (right-to-be-forgotten) tombstones were mis-scoped two ways. (1) `issue_tombstone` defaulted the tenant to `\"default\"` instead of the caller's tenant, so tombstones could be written to the wrong tenant. (2) The read-suppression path — `_get_tombstone_filter` (`routes/facts/common.py`) and the `_tombstone_scope_cache` (`lifecycle/tombstones.py`) — had no `tenant_id` predicate, so tombstone suppression was applied tenant-blind across fact queries and provenance. Reached via `/v1/tombstones` and the fact query/provenance read paths.\n\n### Impact\nCross-tenant integrity of the RTBF mechanism: a tenant's deletion request could be recorded against the wrong tenant, and tombstone suppression could hide — or fail to hide — facts across tenant boundaries, undermining both data-view correctness and RTBF guarantees.\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 passed from `issue_tombstone` into `create_tombstone` (no more `\"default\"` fallback); `AND tenant_id = ?` was added to `_get_tombstone_filter` and `get_tombstone_status`; the suppression cache is re-keyed to include tenant; and all four read call sites thread the caller's tenant. A tenant-B tombstone now suppresses only tenant-B facts and is invisible to tenant-A reads.\n\n### Workarounds\nNone other than upgrading to `0.9.0a12`. Single-tenant deployments are unaffected.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "stigmem-node"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.0a12"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-x26h-xmv8-gxf7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/eidetic-labs/stigmem/pull/728"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/eidetic-labs/stigmem"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-19T21:42:57Z",
    "nvd_published_at" : null
  }
}