Vulnerability · Published Sep 1, 2026 · Assigned by EEF
CVE-2026-82738Ash.Type.UUIDv7 accepts non-v7 UUIDs that then fail to load, causing persistent denial of service
Medium 5.9
In plain English
A medium-severity improper input validation in ash from ash-project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
Official description
Improper Input Validation vulnerability in ash-project ash allows an attacker to persistently deny reads of a record by storing a non-version-7 UUID in an Ash.Type.UUIDv7 attribute. Ash.Type.UUIDv7.cast_input/2 accepts any well-formed UUID string, including non-version-7 UUIDs, and stores it as a 16-byte binary. On read, cast_stored/2 (lib/ash/type/uuid_v7.ex) routes the stored binary back through cast_input/2, which since an input-validation tightening in v3.6.3 matches only version-7 (and optionally version-4) 16-byte binaries and otherwise expects a 36-character string. A stored non-v7 16-byte binary matches neither clause and returns :error, so every later read of that record fails. An attacker able to set such an attribute poisons the row permanently. The fix decodes any 16-byte stored binary directly in cast_stored/2. This issue affects ash: from 3.6.3 before 3.32.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ash-project | ash | 3.6.3 – before 3.32.2 |
| ash-project | ash | 751d8a4d11564efbe358c90c8347f3a00eb60782 – before c453cdc0b8570e86ffef0d10e136247f52b3ea76 |
Weakness: CWE-20 · Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N