Vulnerability Description
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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/MalwareTech/ComoDoS
- https://malwaretech.com/2026/06/exploiting-a-remote-kernel-vulnerability-in-como
- https://updates.xcitium.com/#note11312
- https://www.vulncheck.com/advisories/xcitium-client-security-comodo-internet-sec
FAQ
What is CVE-2026-49494?
CVE-2026-49494 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 Ins...
How severe is CVE-2026-49494?
CVE-2026-49494 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-49494?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.