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CVE-2026-86813— MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To

Quick assessment

Affected
Unknown MetForm
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MetForm WordPress 插件在 4.1.9 版本之前，未能正确中和用户提交值中的换行符（newline characters）。这些用户输入的值会被放入通知邮件的头部字段中，从而允许未认证的攻擊者向网站在提交字段值被配置为填充头部时发送的邮件中注入额外的邮件头（如 Bcc）。

CVSS 4.8 · Medium EPSS 0.24% · P14

Affected Version Matrix 1

VendorProduct Version RangeStatus
Unknown MetForm < 4.1.9 affected
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I. Basic Information for CVE-2026-86813

Vulnerability Information
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Vulnerability Title
MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Unknown MetForm 0 ~ 4.1.9 -

II. Public POCs for CVE-2026-86813

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III. Intelligence Information for CVE-2026-86813

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Security Blog Posts for CVE-2026-86813 (1)

Same Patch Batch · Unknown · 2026-09-11 · 24 CVEs total

CVE-2026-85116 6.5 MEDIUM Simple CAPTCHA with Cloudflare Turnstile 1.2.2 - 1.42.1 - Unauthenticated Arbitrary Shortc
CVE-2026-82215 5.9 MEDIUM WC PayPay Gateway 0.5 - 0.9.3 - Unauthenticated Payment Bypass via Unverified Webhook
CVE-2026-82213 5.3 MEDIUM Nexi XPay Build 7.6.1 - 7.6.2 - Unauthenticated Saved Payment Token Disclosure via IDOR
CVE-2026-86809 5.3 MEDIUM Persian Elementor < 2.8.2 - Unauthenticated ZarinPal Payment Callback Authority Bypass
CVE-2025-15695 GTranslate < 3.0.10 - Admin+ Stored XSS
CVE-2026-14559 Teddy Bear Customize Addon <= 1.0.5 - Unauthenticated Account Takeover
CVE-2026-83545 CoolClock < 4.3.8 - Contributor+ Stored XSS via Custom Skin JSON
CVE-2026-83546 CoolClock < 4.3.8 - Contributor+ Stored XSS via Skin Class Attribute
CVE-2026-14566 Advanced Customized Prompts <= 1.0.1 - Subscriber+ WooCommerce Order Item Metadata Tamperi
CVE-2026-14560 Teddy Bear Customize Addon <= 1.0.5 - Unauthenticated Arbitrary File Upload
CVE-2026-14565 Advanced Customized Prompts <= 1.0.1 - Subscriber+ Stored XSS via Product Popup Configurat
CVE-2026-14563 Advanced Customized Prompts <= 1.0.1 - Unauthenticated Account Takeover
CVE-2026-14562 Teddy Bear Customize Addon <= 1.0.5 - Unauthenticated Order Data Disclosure
CVE-2026-74925 MultiVendorX 5.0.0 - 5.0.15 - Store Owner+ Privilege Escalation to Administrator
CVE-2026-85677 Gutenverse News < 3.3.3 - Unauthenticated Stored XSS via Comment Content
CVE-2026-85678 AI Builder 2.4.1 - 2.7.7 - Contributor+ Stored XSS via Post JavaScript
CVE-2026-82305 YITH WooCommerce Wishlist < 4.18.1 - Unauthenticated Arbitrary Wishlist Rename via change_
CVE-2026-86781 SSL Zen < 4.7.40 - Subscriber+ TLS Private Key Disclosure
CVE-2026-86780 Featured Image with URL < 1.0.6 - Contributor+ Stored XSS via Image Alt Text
CVE-2026-86779 Visualizer < 4.0.6 - Contributor+ Arbitrary Chart Deletion via deleteChart

Showing top 20 of 24 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: MetForm
Same vendor: Unknown

V. Comments for CVE-2026-86813

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