CVE-2026-82727
AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message
Published Aug 31, 2026
CVSS 4.0 · 2.3 Low
EPSS < 1%
KEV · Not listed
Description
Generation of Error Message Containing Sensitive Information vulnerability in ash-project ash_phoenix writes the entire raw submitted param map into an exception message, so secrets submitted alongside a union form field leak into logs, crash reports and the dev error page.
When AshPhoenix.Form.Auto builds a union sub-form and the submitted _union_type does not match a configured type, both raise sites built the message with inspect(params, pretty: true), embedding the full untrusted param map, and also inspected the internal union constraints[:types]. Because the message is constructed by the library rather than Phoenix's parameter logger, config :phoenix, :filter_parameters never redacts it. An attacker controls both the trigger and the contents: submitting %{"_union_type" => "nope", "password" => "..."} puts the password verbatim in the raised message. The fix reports only the offending _union_type and the valid type names, dropping the param and constraints dumps.
This issue affects ash_phoenix: from 1.2.17 before 2.3.25.
When AshPhoenix.Form.Auto builds a union sub-form and the submitted _union_type does not match a configured type, both raise sites built the message with inspect(params, pretty: true), embedding the full untrusted param map, and also inspected the internal union constraints[:types]. Because the message is constructed by the library rather than Phoenix's parameter logger, config :phoenix, :filter_parameters never redacts it. An attacker controls both the trigger and the contents: submitting %{"_union_type" => "nope", "password" => "..."} puts the password verbatim in the raised message. The fix reports only the offending _union_type and the valid type names, dropping the param and constraints dumps.
This issue affects ash_phoenix: from 1.2.17 before 2.3.25.
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| ash-project | ash_phoenix | unaffected |
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| ash-project | ash_phoenix | unaffected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ash-project | Ash Phoenix |
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Remediation
Tracking
Advisories
Metrics
Attack Vector Network
Attack Complexity Low
Privileges Required Low
Attack Requirements Present
User Interaction None
Vulnerable System Confidentiality Impact Low
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.466% probability within 30 days)
Exploitation poc
Automatable no
Technical Impact partial
References
History
Aug 31, 2026 3:30 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
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| Metrics |
ssvc
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Aug 31, 2026 3:30 AM
Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Generation of Error Message Containing Sensitive Information vulnerability in ash-project ash_phoenix writes the entire raw submitted param map into an exception message, so secrets submitted alongside a union form field leak into logs, crash reports and the dev error page. When AshPhoenix.Form.Auto builds a union sub-form and the submitted _union_type does not match a configured type, both raise sites built the message with inspect(params, pretty: true), embedding the full untrusted param map, and also inspected the internal union constraints[:types]. Because the message is constructed by the library rather than Phoenix's parameter logger, config :phoenix, :filter_parameters never redacts it. An attacker controls both the trigger and the contents: submitting %{"_union_type" => "nope", "password" => "..."} puts the password verbatim in the raised message. The fix reports only the offending _union_type and the valid type names, dropping the param and constraints dumps. This issue affects ash_phoenix: from 1.2.17 before 2.3.25. | |
| Title | AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message | |
| First Time appeared |
Ash-project
Ash-project ash Phoenix |
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| Weaknesses | CWE-209 | |
| CPEs | cpe:2.3:a:ash-project:ash_phoenix:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Ash-project
Ash-project ash Phoenix |
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| References |
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| Metrics |
cvssV4_0
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Subscriptions
Weaknesses