---
cve: "CVE-2026-115635"
severity: "MEDIUM"
cvss: 6.0
epss: "0.3%"
vendor: "ash-project"
kev: false
exploited: false
published: "2026-10-25 20:16:32"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-28T19:20:36+01:00"
---

# CVE-2026-115635

> 6.0 MEDIUM · 🧪 PoC

## Beschreibung

Incorrect Authorization vulnerability in ash-project ash_postgres allows a user to read another tenant's record through a skipped upsert.

When Ash.bulk_create/4 or a single create runs as an upsert with return_skipped_upsert?: true and the upsert is skipped (for example because its upsert_condition does not hold), AshPostgres.DataLayer reads the existing row back by the upsert identity in do_bulk_create/3 and upsert/4. That lookup did not apply the resource's attribute multitenancy, so on a resource using strategy :attribute it could match and return the row of another tenant with the same identity values, exposing its fields to the caller.

This issue affects ash_postgres: from 2.6.22 before 2.15.2.

## CNA-Record (Kanon, cvelistV5)

- CNA: **EEF**
- State: PUBLISHED
- Stand: 2026-10-26 14:35:21
- CNA-CVSS: **6.0** (`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`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **CWE-863** — Incorrect Authorization
  The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

## Patch verfügbar (OSV)

- 4c46f5fa4631d569240eda88cffdbc9cb47b3d22 (Commit)
- 8aa81220c401cae412d21078d11b3519ea25d3a9 (Commit)

## Referenzen

- <https://github.com/ash-project/ash/security/advisories/GHSA-36hg-wwp2-fg8w>
- <https://cna.erlef.org/cves/CVE-2026-115635.html>
- <https://osv.dev/vulnerability/EEF-CVE-2026-115635>
- <https://github.com/ash-project/ash_postgres/commit/af0903f1380468bbe1b61fe65acb33772b5e24a5>
- <https://github.com/ash-project/ash_postgres/commit/8aa81220c401cae412d21078d11b3519ea25d3a9>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-115635/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_