CVE-2026-82727 — AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Ash-project Ash Phoenix).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Ash-project | Ash Phoenix | ≥ 1.2.17 and < 2.3.25≥ a3436fcc321e3b34c242cceaf62c3c92bc1a452b and < 0c1775c3cf8988f9abd10a8f92315afc5f06f16d | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 2.3 | CVSS 4.0 | Low | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 2.3 | CVSS 4.0 | Low | — | — | EEF via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for anomalous data read/export volumes and access to sensitive records.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · ash-project/ash phoenix
- SSVC assessment updated
- Record published
- CVSS changed · 2.3
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-82725 AshPhoenix FilterForm allows filtering across non-public relationships, disclosing private related data Aug 31, 2026
- Medium CVE-2026-82726 AshPhoenix get_subdomain maps a crafted or differently-cased Host header to an arbitrary tenant Aug 31, 2026
- High CVE-2026-82724 Broken access control in AshPhoenix SubdomainHook via a nil tenant in handle_subdomain Aug 31, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-82727 is "AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message", rated Low. It affects Ash Phoenix (Ash-project); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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