Vulnerability in Useplunk Plunk

CVE-2026-34975

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 attach…

Vulnerability class: CRLF Injection

EPSS: 0.000 (13.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-34975?
CVE-2026-34975 is a high-severity vulnerability in Useplunk Plunk, classified under CRLF Injection. CVSS score: 8.5/10. Published 2026-04-06.
How severe is CVE-2026-34975?
High severity. CVSS v3 base score is 8.5 out of 10.
Is CVE-2026-34975 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.