CVE-2026-49494 (GCVE-0-2026-49494)

Vulnerability from cvelistv5 – Published: 2026-06-07 12:08 – Updated: 2026-06-07 12:08
VLAI
Title
Comodo Internet Security Inspect.sys IPv6 Integer Underflow Remote Denial of Service
Summary
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).
Severity
8.7 (High)
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
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
References
Impacted products
Vendor Product Version
Comodo Comodo Internet Security Affected: 0 , ≤ 12.3.4.8162 (custom)
Create a notification for this product.
Date Public
2026-06-03 00:00
Credits
Marcus Hutchins (MalwareTech)
Show details on NVD website
To clipboard 

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    "dateReserved": "2026-05-31T11:54:34.993Z",
    "dateUpdated": "2026-06-07T12:08:59.492Z",
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  }
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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