Argus Monitor Local Denial-of-Service Vulnerability (CVE-2026-79417)
CVE-2026-79417 is a local denial-of-service vulnerability in Argus Monitor caused by an exposed IOCTL that allows unprivileged users to disable the x86 MONITOR and MWAIT instructions. Exploiting this requires leveraging a time-of-check to time-of-use (TOCTOU) bug related to the SeLocateProcessImageName function. The vulnerability triggers a HYPERVISOR_ERROR bugcheck, impacting Hyper-V and other kernel components relying on these instructions.
AI Analysis
Technical Summary
This vulnerability involves an exposed IOCTL interface in Argus Monitor that permits unprivileged users to disable the x86 MONITOR and MWAIT instructions, which are used by Hyper-V and other kernel components. The exploit path requires exploiting a TOCTOU bug, possibly due to poor documentation of the SeLocateProcessImageName function. The IOCTL security relies on an obscured encryption scheme involving a SHA-256 KDF-derived XOR keystream and CRC16 checksum, which was reimplemented in the proof of concept. Triggering the vulnerability results in a HYPERVISOR_ERROR bugcheck, causing a local denial-of-service condition.
Potential Impact
Successful exploitation causes a local denial-of-service by triggering a hypervisor error bugcheck, disrupting Hyper-V and other kernel components that depend on the MONITOR and MWAIT instructions. There is no indication of privilege escalation or remote exploitation. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict local access to trusted users to prevent exploitation. No vendor advisory or official patch information is currently provided.
Argus Monitor Local Denial-of-Service Vulnerability (CVE-2026-79417)
Description
CVE-2026-79417 is a local denial-of-service vulnerability in Argus Monitor caused by an exposed IOCTL that allows unprivileged users to disable the x86 MONITOR and MWAIT instructions. Exploiting this requires leveraging a time-of-check to time-of-use (TOCTOU) bug related to the SeLocateProcessImageName function. The vulnerability triggers a HYPERVISOR_ERROR bugcheck, impacting Hyper-V and other kernel components relying on these instructions.
Reddit Discussion
(1) An exposed IOCTL lets unprivileged users disable the x86 MONITOR & MWAIT instructions used by Hyper-V and other kernel components--triggering a HYPERVISOR_ERROR bugcheck.
(2) Reaching the IOCTL requires exploiting a TOCTOU bug arguably caused by poor documentation of the SeLocateProcessImageName function.
(3) Reimplementation of the driver's security through obscurity IOCTL encryption scheme: SHA-256 KDF-derived XOR keystream & CRC16 Checksum.
See full write-up, and Github for PoC.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves an exposed IOCTL interface in Argus Monitor that permits unprivileged users to disable the x86 MONITOR and MWAIT instructions, which are used by Hyper-V and other kernel components. The exploit path requires exploiting a TOCTOU bug, possibly due to poor documentation of the SeLocateProcessImageName function. The IOCTL security relies on an obscured encryption scheme involving a SHA-256 KDF-derived XOR keystream and CRC16 checksum, which was reimplemented in the proof of concept. Triggering the vulnerability results in a HYPERVISOR_ERROR bugcheck, causing a local denial-of-service condition.
Potential Impact
Successful exploitation causes a local denial-of-service by triggering a hypervisor error bugcheck, disrupting Hyper-V and other kernel components that depend on the MONITOR and MWAIT instructions. There is no indication of privilege escalation or remote exploitation. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict local access to trusted users to prevent exploitation. No vendor advisory or official patch information is currently provided.
Technical Details
- Source Type
- Subreddit
- netsec
- Reddit Score
- 0
- Discussion Level
- minimal
- Content Source
- reddit_link_post
- Post Type
- link
- Newsworthiness Assessment
- {"score":48,"reasons":["external_link","newsworthy_keywords:vulnerability,cve-","security_identifier","established_author","very_recent"],"isNewsworthy":true,"foundNewsworthy":["vulnerability","cve-"]}
- Has External Source
- true
- Trusted Domain
- false
Threat ID: 6ab5d9c4f7a7c5410633fd59
Added to database: 09/25/2026, 02:17:40 UTC
Last enriched: 09/25/2026, 02:17:44 UTC
Last updated: 09/25/2026, 03:17:33 UTC
Views: 4
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