CVE-2026-34975
8.5 · HIGHOverview
CVE-2026-34975 is a high-severity vulnerability affecting useplunk plunk. It was published on April 6, 2026 and has a CVSS 3.1 base score of 8.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
Plunk is an open-source email platform built on top of AWS SES. Prior to 0.8.0, a CRLF header injection vulnerability was discovered in SESService.ts, where user-supplied values for from.name, subject, custom header keys/values, and attachment filenames were interpolated directly into raw MIME messages without sanitization. An authenticated API user could inject arbitrary email headers (e.g. Bcc, Reply-To) by embedding carriage return/line feed characters in these fields, enabling silent email forwarding, reply redirection, or sender spoofing. The fix adds input validation at the schema level to reject any of these fields containing \r or \n characters, consistent with the existing validation already applied to the contentId field. This vulnerability is fixed in 0.8.0.
Remediation
Check the references section for vendor advisories and patches from useplunk. Update plunk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| useplunk | plunk | >= 0, < 0.8.0 | Affected |
Frequently Asked Questions
What is CVE-2026-34975?
CVE-2026-34975 is a high-severity vulnerability affecting useplunk plunk. It was published on April 6, 2026 and has a CVSS 3.1 base score of 8.5 (HIGH).
How severe is CVE-2026-34975?
This vulnerability has a CVSS 3.1 base score of 8.5, rated HIGH. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-34975?
Check the references section for vendor advisories and patches from useplunk. Update plunk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-34975?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-34975 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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