# CVE-2026-82753 — ash-project ash_authentication_oauth2_server

> As of 2026-09-08, CVE-2026-82753 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in ash-project ash_authentication_oauth2_server, CVSS v4.0 8.2, EPSS 0.4% (33.4th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-82753 as of 2026-09-08; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-09-08

## What is CVE-2026-82753?

Allocation of Resources Without Limits or Throttling vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to exhaust database storage and memory. The /authorize endpoint is unauthenticated by design. With Client ID Metadata Documents enabled, resolve_client/3 in AshAuthentication.Oauth2Server.CIMD fetches the document for each new URL-shaped client_id and upserts a client row, with no cap on the number of rows, no expiry or garbage collection, and no length bound on the fetched fields; the document was also placed in CIMD.Cache before validation, so even rejected documents held cache memory until their TTL. An attacker serving valid documents at many distinct URLs creates one permanent client row per URL, each able to carry multi-megabyte strings, growing storage and memory without bound. This issue affects ash_authentication_oauth2_server: from 0.3.0 before 0.3.1.

The record classifies CVE-2026-82753 under weakness class [CWE-770](https://intel.threadlinqs.com/cwe/CWE-770). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 28 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 8.2 — High (derived from score) (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 33.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-07, last modified 2026-09-08

## Is CVE-2026-82753 being exploited?

It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [ash-project](https://intel.threadlinqs.com/vendors/ash-project): ash_authentication_oauth2_server

## How to fix CVE-2026-82753

No vendor patch reference has been recorded for CVE-2026-82753 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-82753

No threat campaign in the Threadlinqs corpus currently references CVE-2026-82753, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on 2026-09-08.

**Vendor advisory and patch**

- [github.com — vendor advisory](https://github.com/ash-project/ash_authentication_oauth2_server/security/advisories/GHSA-9pv3-wxjm-f846)
- [github.com — patch](https://github.com/ash-project/ash_authentication_oauth2_server/commit/45e24f69e0f95d67413e2508acc2264156acb5ac)

**Other references**

- [cna.erlef.org — related](https://cna.erlef.org/cves/CVE-2026-82753.html)
- [osv.dev — related](https://osv.dev/vulnerability/EEF-CVE-2026-82753)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-82753
Full detection coverage and IOCs for threats exploiting CVE-2026-82753 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp