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Fencer Intel
low 3.7

CVE-2026-86834 json

MetForm 2.2.1 - 4.3.0 - Unauthenticated Debug File Disclosure via HubSpot Forms Integration

published last mo. modified last mo. also EUVD-2026-91940

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

The MetForm WordPress plugin before 4.3.1 does not properly restrict access to a debug file it writes to the web root on every form submission when its HubSpot Forms integration is enabled, allowing unauthenticated attackers to read upstream API response data, including correlation identifiers and cookies.

Patch / fix

  • Unknown MetForm 4.3.1

Is CVE-2026-86834 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/a56b7e26-9070-4c38-bdc1-7289b5829638/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

  • Unknown MetForm

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
Technology feeds

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.