CVE-2025-62691Network attack vector

SYSTEM code execution via HTTP header overflow

Published Nov 25, 2025 · Updated Nov 25, 2025

Stack-based buffer overflow in Intercom MaLion and MaLionCloud Windows agents allows remote attackers to execute code as SYSTEM via HTTP headers. Intercom has disclosed that crafted header data corrupts a stack buffer during the agent's HTTP request handling, but has not named the affected parser or copy operation. No authentication or user interaction is required, and successful exploitation grants control of the Windows endpoint with SYSTEM privileges.

CVSS severity9.8
Critical
EPSS probability0.68%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Intercom MaLion and MaLionCloud Windows agents allows remote attackers to execute code as SYSTEM via HTTP headers. Intercom has disclosed that crafted header data corrupts a stack buffer during the agent's HTTP request handling, but has not named the affected parser or copy operation. No authentication or user interaction is required, and successful exploitation grants control of the Windows endpoint with SYSTEM privileges.

The record

CVE
CVE-2025-62691
Published
Nov 25, 2025
Updated
Nov 25, 2025
Vendor
Intercom, Inc.
Product
Security Point (Windows) of MaLion
Classifications
CWE-121, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 25, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=prior to Ver.7.1.1.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Intercom, Inc. · Security Point (Windows) of MaLionversion=prior to Ver.7.1.1.9
Intercom, Inc. · Security Point (Windows) of MaLionCloudversion=prior to Ver.7.2.0.1

Published CVSS scores

9.3JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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