CVE-2026-86813: MetForm (WordPress plugin) · CRLF Injection
Affects MetForm (WordPress plugin)Source CVE Database V5
Not known to be exploited · CVSS 4.8 Medium : upgrade to 4.1.9 when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.1.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade MetForm (WordPress plugin) to 4.1.9.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MetForm | Affected
| Fixed in
|
AI-suggested
Upgrade MetForm to version 4.1.9 or later, where this vulnerability is fixed. Since the vulnerability is patched in 4.1.9, applying this official fix fully mitigates the issue. No other specific mitigations are indicated.
Description
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.