What’s Vulnerable › Vulnerabilities

CVE-2026-57511: SuperPlane < 0.30.0 SMTP Header Injection via Webhook Event Title

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-28 · updated 2026-10-23
• Weakness: CWE-93

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.

Affected products

• superplanehq superplane: before 0.30.0 — fixed in 0.30.0

How to fix

Upgrade to a fixed version: superplanehq superplane 0.30.0. Check the vendor advisory for mitigations.

References

• https://github.com/superplanehq/superplane/commit/428c559dd2fa0aef3ba825a434a1b05c9abc7df7
• https://github.com/superplanehq/superplane/pull/6354
• https://github.com/superplanehq/superplane/releases/tag/v0.30.0
• https://www.vulncheck.com/advisories/superplane-smtp-header-injection-via-webhook-event-title

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