CVE-2026-82726Network attack vectorHinoki check available

Tenant selection via permissive Host-header matching

Published Aug 31, 2026 · Updated Aug 31, 2026

Permissive regex matching in Ash Framework AshPhoenix 2.1.26 through 2.3.24 allows remote attackers to select a tenant via a crafted Host header. AshPhoenix.Helpers.get_subdomain/2 interpolates root_host into an unanchored global regex, so wildcards, metacharacters, or case differences strip arbitrary text from conn.host. Applications that use subdomain multitenancy expose this path, allowing cross-tenant selection; malformed or nil root-host settings can instead fail requests.

CVSS severity6.3
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Permissive regex matching in Ash Framework AshPhoenix 2.1.26 through 2.3.24 allows remote attackers to select a tenant via a crafted Host header. AshPhoenix.Helpers.get_subdomain/2 interpolates root_host into an unanchored global regex, so wildcards, metacharacters, or case differences strip arbitrary text from conn.host. Applications that use subdomain multitenancy expose this path, allowing cross-tenant selection; malformed or nil root-host settings can instead fail requests.

The record

CVE
CVE-2026-82726
Published
Aug 31, 2026
Updated
Aug 31, 2026
Vendor
Ash Framework
Product
AshPhoenix
Classifications
CWE-178, CWE-625, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.1.26 <2.3.25
  2. Affected versionversion=9a5ea4d377bc263de321d79574872a3dfc4fb541 <8306f29e77526840c89f3cd244996ce7c0fa2cda

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ash Framework · AshPhoenixversion=2.1.26 <2.3.25; version=9a5ea4d377bc263de321d79574872a3dfc4fb541 <8306f29e77526840c89f3cd244996ce7c0fa2cda

Published CVSS scores

6.3EEF CNACVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-178Improper Handling of Case Sensitivity
CWE-625Permissive Regular Expression
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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