CVE-2026-49494Public exploitNetwork attack vector

Remote system crash via IPv6 length underflow

Published Jun 7, 2026 · Updated Jun 7, 2026

Integer underflow in Inspect.sys in Comodo Internet Security 12.3.4.8162 and earlier allows remote attackers to crash Windows via IPv6 packets. The IPv6 parser subtracts each extension-header length from an attacker-controlled unsigned payload length without checking for wraparound. Unauthenticated network reachability to the host's IPv6 interface is sufficient because parsing precedes firewall rules; one crafted packet triggers a Windows kernel BSOD, with no reported confidentiality or integrity impact.

CVSS severity8.7
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Inspect.sys in Comodo Internet Security 12.3.4.8162 and earlier allows remote attackers to crash Windows via IPv6 packets. The IPv6 parser subtracts each extension-header length from an attacker-controlled unsigned payload length without checking for wraparound. Unauthenticated network reachability to the host's IPv6 interface is sufficient because parsing precedes firewall rules; one crafted packet triggers a Windows kernel BSOD, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2026-49494
Published
Jun 7, 2026
Updated
Jun 7, 2026
Vendor
Comodo Group, Inc.
Product
Comodo Internet Security
Classifications
CWE-191, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 7, 2026Record 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=0 <=12.3.4.8162

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Comodo Group, Inc. · Comodo Internet Securityversion=0 <=12.3.4.8162

Published CVSS scores

7.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1499.004Application or System Exploitation

Public exploit references

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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