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TI-2026-57074 Aliases CVE-2026-82756

Improper output encoding in ash-project ash_authentication_oauth2_server

Priority LOW 29CWE-116Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Improper Encoding or Escaping of Output vulnerability in ash-project ash_authentication_oauth2_server allows an unauthenticated attacker to inject arbitrary authentication parameters into the WWW-Authenticate challenge header. BearerPlug and RequireScopePlug built the Bearer resource_metadata="..." challenge by interpolating a resource_metadata URL derived from the request tenant directly into the quoted value. In a multi-tenant application that sets the Ash tenant from request-controlled data (a subdomain, the Host, a path segment, or a header), a tenant containing a " closes the quoted value and appends attacker-chosen auth-params, including a second resource_metadata URL pointing at an attacker-controlled authorization server that spec-following clients follow. Carriage returns and line feeds are rejected by Plug, so this is parameter injection within one header, not response splitting. This issue affects ash_authentication_oauth2_server: from 0.1.3 before 0.3.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0068 52nd percentileScored 2026-11-07
Fix Fixed ash_authentication_oauth2_server (ash-project): 0.3.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ash-projectash_authentication_oauth2_server0.1.3 to before 0.3.10.3.1Patch availableCNA
  • ash_authentication_oauth2_server Vendorash-project Affected 0.1.3 to before 0.3.1 Fixed in 0.3.1 Patch available CNA

CPE names CNA · 1

CPEVersionsRoleVendor
cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:*———
  • cpe:2.3:a:ash-project:ash_authentication_oauth2_server:*:*:*:*:*:*:*:* Versions — — ·—

Remediation

  • Fix · CNA ash_authentication_oauth2_server (ash-project) Fixed in 0.3.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    ash-project ash_authentication_oauth2_server 0.3.1

    6 records Highest priority Priority LOW 6 LOW

    Other records, highest priority first

    • TI-2026-57071 Resource allocation without limits in ash-project ash_authentication_oauth2_serverPriority LOW 37
    • TI-2026-57076 Improper authentication in ash-project ash_authentication_oauth2_serverPriority LOW 29
    • TI-2026-57075 ash_authentication_oauth2_server CIMD fetcher classifies IPv4-in-IPv6 and site-local addresses as public, allowing SSRFPriority LOW 29
    Show all 6 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-82756

References

Patch 1

Advisory 1

Other 2

  • TI-2026-56298 Query-complexity limit bypass via first/last pagination arguments in AshGraphql enables denial of service CVSS 4.0HIGH 8.7
  • TI-2026-52572 Unbounded atom creation from client-supplied RPC field names in AshTypescript field formatter CVSS 4.0HIGH 8.7
  • TI-2026-57010 Path traversal in AshAdmin file uploads via unsanitized client filename CVSS 4.0HIGH 8.3
  • TI-2026-26840 Ash Framework: Ash.Type.Module.cast_input/2 atom exhaustion via unchecked Module.concat allows BEAM VM crash CVSS 4.0HIGH 8.2
  • TI-2026-54252 EEx template evaluation of prompt content in AshAi enables remote code execution CVSS 4.0HIGH 8.9
  • TI-2026-54208 Stored XSS in AshAdmin relationship typeahead via unescaped label_field content CVSS 4.0HIGH 8.4
See all 90 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences