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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-49494 Detail

Description

Comodo Internet Security's firewall driver Inspect.sys contains an integer underflow in its IPv6 packet parser. The parser decrements an unsigned 64-bit payload-length value (taken from the IPv6 fixed header's payload length field) by the size of each IPv6 extension header without validating it, so a packet whose declared payload length is smaller than the sum of its extension-header lengths underflows the value to a near-maximal 64-bit integer. Because IPv6 parsing occurs before firewall rule enforcement, a remote, unauthenticated attacker can send a single crafted IPv6 packet - even to a host with all ports blocked - to trigger an out-of-bounds read (and, on a separate code path, an oversized memcpy) in the Windows kernel at DISPATCH_LEVEL, crashing the system (BSOD).


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulnCheck
CVSS-B 8.7 HIGH
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/MalwareTech/ComoDoS VulnCheck
https://malwaretech.com/2026/06/exploiting-a-remote-kernel-vulnerability-in-comodo-internet-security.html VulnCheck
https://www.vulncheck.com/advisories/comodo-internet-security-inspect-sys-ipv6-integer-underflow-remote-denial-of-service VulnCheck

Weakness Enumeration

CWE-ID CWE Name Source
CWE-191 Integer Underflow (Wrap or Wraparound) VulnCheck  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-49494
NVD Published Date:
06/07/2026
NVD Last Modified:
06/07/2026
Source:
VulnCheck