XSS in Useplunk Plunk

CVE-2026-42192

Plunk is an open-source email platform built on top of AWS SES. Prior to version 0.9.0, a stored cross-site scripting (XSS) vulnerability exists in the campaign management feature, where the email body content created by authenticated project members is stored and later rendered in the admin dashboard using React's dangerouslySetInnerHTML without any HTML sanitization. This allows a lower-privileged member to embed malicious scripts in a campaign's email body that execute in the context of any admin or other member who views the campaign, potentially enabling session hijacking or unauthorized actions on their behalf. This issue has been patched in version 0.9.0.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42192: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42192?
CVE-2026-42192 is a medium-severity vulnerability in Useplunk Plunk, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-05-08.
How severe is CVE-2026-42192?
Medium severity. CVSS v3 base score is 5.4 out of 10.