PatchTheCVECVE-2026-57511: SuperPlane before 0.30.0 contains an SMTP header injection vulnerability that allows unauthenticated attackers
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Routine
MEDIUM 5.4REMOTE
CVE-2026-57511 is a medium-severity flaw (CVSS 5.4) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 bou
Why this priority
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.4 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 67%) |
| CISA exploited list | No |
| Weakness | CWE-93 |
| Published | 2026-07-28 |
| Last modified | 2026-10-23 |
Publisher (CNA): VulnCheck
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.