CVE-2026-49494 (GCVE-0-2026-49494)
Vulnerability from cvelistv5 – Published: 2026-06-07 12:08 – Updated: 2026-06-23 14:07
VLAI
EPSS
VEX
Title
Xcitium Client Security / Comodo Internet Security Remote Denial of Service
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-08 15:16 UTC
CWE
- CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
VulnCheck
CNA
References
4 references
| URL | Tags |
|---|---|
| https://malwaretech.com/2026/06/exploiting-a-remo… | technical-descriptionexploit |
| https://github.com/MalwareTech/ComoDoS | exploit |
| https://updates.xcitium.com/#note11312 | release-notespatch |
| https://www.vulncheck.com/advisories/xcitium-clie… | third-party-advisory |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Xcitium (formerly Comodo Security Solutions) | Comodo Internet Security |
Affected:
0 , ≤ 12.3.4.8162
(custom)
|
|
| Xcitium | Xcitium Client Security (XCS) |
Affected:
0 , < 13.8.2.10019
(custom)
|
Date Public
2026-06-03 00:00
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