CVE-2026-57511 SuperPlane < 0.30.0 SMTP Header Injection via Webhook Event Title
Unauthenticated attackers can inject SMTP headers via webhook titles to exfiltrate data or bypass email security checks in SuperPlane.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-57511?
CVE-2026-57511 is a medium-severity vulnerability in superplanehq superplane, published on 28 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-93
Which versions are affected by CVE-2026-57511?
How do I fix CVE-2026-57511?
No fix has been published for CVE-2026-57511 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-57511 being exploited?
There is no known exploitation of CVE-2026-57511 in the wild and no public exploit code.
Sources
Also known as GHSA-c3mp-rj38-mpvh.