CVE-2026-49494
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
Summary
Xcitium Client Security (XCS) before 13.8.2.10019 and Comodo Internet Security (CIS) through 12.3.4.8162 (fix expected by 2026 Q3) contain an integer underflow vulnerability in the firewall driver Inspect.sys that allows remote unauthenticated attackers to crash the system by sending a crafted IPv6 packet with a declared payload length smaller than the sum of its extension-header lengths. The unsigned 64-bit payload-length value underflows to a near-maximal integer, triggering an out-of-bounds read and oversized memcpy in the Windows kernel at DISPATCH_LEVEL, resulting in a blue screen of death even on hosts with all ports blocked.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Xcitium (formerly Comodo Security Solutions) | Comodo Internet Security | 0 <= 12.3.4.8162 | affected |
| Xcitium | Xcitium Client Security (XCS) | 0 < 13.8.2.10019 | affected |
Weaknesses
- CWE-191: Integer Underflow (Wrap or Wraparound)
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: poc
- Automatable: yes
- Technical Impact: partial
References
- https://malwaretech.com/2026/06/exploiting-a-remote-kernel-vulnerability-in-comodo-internet-security.html
- https://github.com/MalwareTech/ComoDoS
- https://updates.xcitium.com/#note11312
- https://www.vulncheck.com/advisories/xcitium-client-security-comodo-internet-security-remote-dos
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