Vulnerability in Superplanehq Superplane

CVE-2026-57511

SuperPlane before 0.30.0 contains an SMTP header injection vulnerability that allows unauthenticated attackers to inject arbitrary SMTP headers by including CRLF sequences in the event payload title field delivered via webhook. Attackers can manipulate the unsanitized title field passed to the SMTP DATA command to add Bcc recipients for content exfiltration, forge the From address to bypass SPF and DKIM checks, or inject Content-Type and MIME boundary headers to corrupt message bodies for phishing.

Vulnerability class: CRLF Injection

EPSS: 0.002 (14.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-57511?
CVE-2026-57511 is a medium-severity vulnerability in Superplanehq Superplane, classified under CRLF Injection. CVSS score: 5.4/10. Published 2026-07-28.
How severe is CVE-2026-57511?
Medium severity. CVSS v3 base score is 5.4 out of 10.