CVE-2026-57511

Severity CVSS v4.0:

MEDIUM

Type:

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Publication date:

28/07/2026

Last modified:

28/07/2026

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.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 6.30 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): Present
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): None
Confidentiality (SC): Low
Integrity (SI): Low
Availability (SA): None

Base Score 4.0

6.30

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.40 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): Low
Integrity (I): Low
Availability (A): None

Base Score 3.x

5.40

Severity 3.x

MEDIUM

CVE-2026-57511

Description

Impact

References to Advisories, Solutions, and Tools