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Fencer Intel
medium 4.8

CVE-2026-86813 json

MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To

published 2mo ago modified 2mo ago also EUVD-2026-76041

cvss
4.8
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 15%
public exploits
0
none known

Summary

The MetForm WordPress plugin before 4.1.9 does not properly neutralize newline characters in user-submitted values that are placed into notification email headers, allowing unauthenticated attackers to inject additional email headers, such as Bcc, into the emails the site sends when a submitted field value is configured to populate a header.

Patch / fix

  • Unknown MetForm 4.1.9

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/afda2a26-b965-42cb-85a8-4a4d83ec026e/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

  • Unknown MetForm

Classification

Weakness
  • CWE-93 Improper Neutralization of CRLF Sequences
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.