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Fencer Intel
low 2.3

CVE-2026-82727 json

AshPhoenix Form.Auto leaks submitted params in an unknown _union_type error message

published 2mo ago modified 2mo ago also EEF-CVE-2026-82727 , EUVD-2026-68334 , GHSA-5xf4-hgcq-xw7v

cvss
2.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

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.

Patch / fix

  • hex ash_phoenix 2.3.25
  • ash-project ash_phoenix 2.3.25

Is CVE-2026-82727 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/ash-project/ash_phoenix/security/advisories/GHSA-5xf4-hgcq-xw7v referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 2.3 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
CNA 4.0 2.3 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

Affected packages

ecosystem package affected fixed in
hex ash_phoenix
>=1.2.17, <2.3.25
2.3.25

Affected products

  • ash-project ash_phoenix

Classification

Weakness
  • CWE-209 Generation of Error Message Containing Sensitive Information

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of ash-project/ash_phoenix published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.