CVE-2026-49494

Published: Giu 07, 2026 Last Modified: Giu 07, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,7
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A
HIGH 7,5
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high

Description

AI Translation Available

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).

191

Integer Underflow (Wrap or Wraparound)

Draft
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality Access Control
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Dos: Instability Modify Memory Execute Unauthorized Code Or Commands Bypass Protection Mechanism
Applicable Platforms
Languages: C, C++, Java, C#
View CWE Details
https://github.com/MalwareTech/ComoDoS
https://malwaretech.com/2026/06/exploiting-a-remote-kernel-vulnerability-in-com…
https://www.vulncheck.com/advisories/comodo-internet-security-inspect-sys-ipv6-…