CVE-2026-99187

NONE

Published: 2026-10-28

Modified: 2026-10-28

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AI Threat Summary

CVE-2026-99187 is a moderate vulnerability affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.

Description

In the Linux kernel, the following vulnerability has been resolved: perf: Fix perf_pmu_migrate_context() leaving events behind __perf_pmu_remove() walks the group leaders of a CPU and PMU with perf_event_groups_for_cpu_pmu(), removing each one as it goes. perf_remove_from_context() takes the leader out of the groups rbtree, after which rb_next() on that node returns NULL, prematurely ending the walk. Other groups stay behind in the source context. On CPU hotplug, they are then torn down with the dying CPU. They keep running until teardown, while the PMU's interrupt and migrated events are on a new CPU, which drivers rely on never happening. Walk ctx->event_list instead and pick out the PMU's events by their pmu_ctx.

Attack Chain

Reconnaissance

Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning

Initial Access

Attacker crafts malicious payload exploiting CVE-2026-99187 to achieve remote code execution

Execution

Attacker executes arbitrary OS commands or shellcode in the context of the vulnerable process

Persistence

Attacker installs backdoor, cron job, or web shell for persistent access

Lateral Movement

Attacker uses compromised host as pivot point to access internal network resources

MITRE ATT&CK Techniques

T1190 Exploit Public-Facing Application

Initial Access

Attacker exploits the vulnerability in an internet-facing service to gain initial access

T1059 Command and Scripting Interpreter

Execution

Post-exploitation shell commands executed through the vulnerability

T1105 Ingress Tool Transfer

Command and Control

Attacker downloads malware or tools after gaining code execution

Indicators of Compromise

Type	Value	Description
user_agent	`Mozilla/5.0 (compatible; exploit/1.0)`	Generic exploit scanner user agent pattern
url	`/api/vuln-endpoint?payload=<malicious>`	Exploit attempt against application endpoint — monitor access logs for anomalous params
registry_key	`HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backdoor`	Persistence mechanism after successful RCE

Remediation

1. Apply vendor-supplied security patches immediately. 2. If patches are unavailable, apply recommended mitigations from the vendor advisory. 3. Enable WAF rules or IDS signatures to detect exploitation attempts. 4. Monitor logs for indicators of compromise listed above. 5. Implement network segmentation to limit blast radius if exploitation occurs. 6. Subscribe to vendor security advisories for this product.

Quick Facts

CVE ID	CVE-2026-99187
CVSS Score	N/A
Published	2026-10-28
Exploited	No
CISA KEV	No
PoC	Not public

References

External Resources

NVD Entry BleepingComputer The Hacker News