CVE-2026-115627 — AshPostgres ignores attribute multitenancy on the join resource when loading many_to_many and through relationships, returning records related through other tenants' rows
Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to load destination records linked to a source record only through another tenant's join rows. When a many_to_many relationship, or a through relationship, is loaded with a lateral join (for example with a per-record limit or sort), AshPostgres.DataLayer builds the query for the join resource, and for each resource along a through path, in lateral_join_query/3 and through_step_queries/4 without running that resource's read action, which is where attribute multitenancy is applied. When those resources use strategy :attribute multitenancy, rows belonging to other tenants were joined, so the load returned destination records that the caller's tenant is not related to. This issue affects ash_postgres: from 0.38.0 before 2.15.2.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Ash-project Ash Postgres).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Ash-project | Ash Postgres | ≥ 0.38.0 and < 2.15.2≥ 7115bec58678f13b1ac2fb4822a0ba1aea9dbec5 and < 8c25c945c39a45299193fe70b09fc2fa2aacac7b | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.0 | CVSS 4.0 | Medium | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 6.0 | CVSS 4.0 | Medium | — | — | EEF via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 26, 2026 → Oct 29, 2026 · 4 reading(s) · max 0.25%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Source status changed · Received → Deferred
- Source status changed · Published → Received
- Record published
- CVSS changed · 6.0
- Source status changed · → Published
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 25, 2026 – Oct 25, 2026
References
5 on the record
- github.com/ash-project/ash_postgres/commit/8c25c945c39a45299193fe70b09fc2fa2aaca
- github.com/ash-project/ash/security/advisories/GHSA-gr2r-f49c-9gm2
- osv.dev/vulnerability/EEF-CVE-2026-115627
- github.com/ash-project/ash_postgres/commit/7115bec58678f13b1ac2fb4822a0ba1aea9db
- cna.erlef.org/cves/CVE-2026-115627.html
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-115635 AshPostgres returns another tenant's record for a skipped upsert when return_skipped_upsert? is set 5d
- High CVE-2026-78699 rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres Aug 30, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-115627 is "AshPostgres ignores attribute multitenancy on the join resource when loading many_to_many and through relationships, returning records related through other tenants' rows", rated Medium. It affects Ash Postgres (Ash-project); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.0 describes technical severity. EPSS 0.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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