Cyber Resilience

CVE-2024-26198

Microsoft Exchange Server 2016 … 2019

Published
12 March 2024
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.068 93th percentile
Risk Priority 71 floored blend · peak EPSS

Summary

CVE-2024-26198 is a high-severity Untrusted Search Path (CWE-426) vulnerability in Microsoft Exchange Server. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked in the top 7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and CM-7 (Least Functionality) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2024-26198 is a remote code execution vulnerability affecting Microsoft Exchange Server. It carries a CVSS 3.1 base score of 8.8 with the vector string AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H and is associated with CWE-426.

An attacker can exploit the flaw over the network without authentication, provided a user performs a required interaction such as clicking a crafted link. Successful exploitation grants the attacker full control over confidentiality, integrity, and availability on the affected Exchange Server.

Microsoft Security Response Center advisories at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-26198 describe available patches and mitigation guidance.

EPSS for the CVE rose from low values to a recorded peak of 0.0524 on 2025-12-11 before receding to the current 0.0269, indicating a period of increased exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Microsoft Exchange Server Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
T1574 Hijack Execution Flow Stealth
Adversaries may execute their own malicious payloads by hijacking the way operating systems run programs.
T1574.001 DLL Stealth
Adversaries may abuse dynamic-link library files (DLLs) in order to achieve persistence, escalate privileges, and evade defenses.
T1574.008 Path Interception by Search Order Hijacking Stealth
Adversaries may execute their own malicious payloads by hijacking the search order used to load other programs.
T1574.007 Path Interception by PATH Environment Variable Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries.
T1574.009 Path Interception by Unquoted Path Stealth
Adversaries may execute their own malicious payloads by hijacking vulnerable file path references.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-21763Same product: Microsoft Exchange Server
CVE-2023-21764Same product: Microsoft Exchange Server
CVE-2023-36778Same product: Microsoft Exchange Server
CVE-2021-26855Same product: Microsoft Exchange Server
CVE-2023-36050Same product: Microsoft Exchange Server
CVE-2022-41040Same product: Microsoft Exchange Server
CVE-2024-49040Same product: Microsoft Exchange Server
CVE-2023-35388Same product: Microsoft Exchange Server
CVE-2023-36745Same product: Microsoft Exchange Server
CVE-2021-26858Same product: Microsoft Exchange Server

Affected Assets

microsoft
exchange server
2016, 2019

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Secure baseline settings can enforce absolute, organization-controlled paths for critical resources.

Least-functionality configuration can prohibit unapproved directories or executables from being reachable via search paths.

Engineering principles such as trusted paths, complete mediation, and least privilege directly require hard-coded or validated search paths instead of external ones.

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-05 full match
prevents

Preventing execution of unauthorized code directly blocks the malicious binaries that an untrusted search path would load.

PR.PS-06 mostly match
prevents

Secure development practices include avoiding or sanitizing externally influenced search paths in application code.

PR.PS-01 partial match
prevents

Hardened configuration baselines can enforce safe search paths and restrict environment variables that enable the weakness.

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.

finds

Security testing can discover search-path issues but does not itself prevent them in production code.

degrades

Restricting software installation reduces the chance that untrusted binaries or libraries are placed in search paths.

prevents

Secure architecture principles include hard-coded or validated search paths and avoiding reliance on untrusted directories.

prevents

Secure coding standards require absolute paths or integrity-checked search paths, directly mitigating CWE-426.

none

Change-management processes can enforce review of path-handling changes, indirectly lowering risk.

References