Cyber Resilience

CVE-2025-40631

Icewarp Mail Server 11.4.0

Published
16 May 2025
Modified
17 June 2026
CVSS Score v4 2.0
Click a component to see what it means
Raw vectorCVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0020 10th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2025-40631 is a low-severity Improper Neutralization of HTTP Headers for Scripting Syntax (CWE-644) vulnerability in Icewarp Mail Server. Its CVSS base score is 2.0 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

HTTP host header injection vulnerability in Icewarp Mail Server affecting version 11.4.0. By modifying the Host header and adding a payload, arbitrary JavaScript code can be executed on page load. The user must interact with a malicious link to be…

more

redirected.

CWE(s)
CWE-644

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-39700Same product: Icewarp Mail Server
CVE-2025-40632Same product: Icewarp Mail Server
CVE-2025-40630Same product: Icewarp Mail Server
CVE-2023-39699Same product: Icewarp Mail Server
CVE-2025-27632Shared CWE-644
CVE-2025-13213Shared CWE-644
CVE-2025-66485Shared CWE-644
CVE-2024-40686Shared CWE-644
CVE-2024-51451Shared CWE-644
CVE-2025-13803Shared CWE-644

Affected Assets

icewarp
mail server
11.4.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V4.2.3

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly requires checking/neutralizing untrusted data such as HTTP headers before they reach browser components.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper output encoding and header sanitization to prevent scripting injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing catches header-injection issues before release, covering most of the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and output encoding that directly prevents header-injection flaws.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for neutralizing untrusted data in HTTP headers.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce injection surfaces but do not prescribe header-specific controls.

A.8.28 Secure coding partial match
prevents

Secure coding standards require proper escaping or rejection of scripting syntax in HTTP headers.

References