CVE-2026-117866

NONE
Published: 2026-10-27
Modified: 2026-10-27
Enriched via mock
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AI Threat Summary

CVE-2026-117866 is a moderate vulnerability affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.

Description

Privilege escalation due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

Attack Chain
1
Initial Access

Attacker has low-privilege local access (e.g., via phishing or compromised service account)

2
Privilege Escalation

Attacker exploits CVE-2026-117866 to escalate from low-privilege user to root/SYSTEM/admin

3
Defense Evasion

Elevated privileges used to disable security controls, clear logs, and establish persistence

4
Impact

Full system compromise achieved; attacker can install ransomware, exfiltrate all data, or pivot

MITRE ATT&CK Techniques
T1068 Exploitation for Privilege Escalation
Privilege Escalation

Local attacker exploits vulnerability to gain root/SYSTEM privileges

T1134 Access Token Manipulation
Privilege Escalation

Elevated token used to impersonate high-privilege accounts

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
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-2026-117866
CVSS Score N/A
Published 2026-10-27
Exploited No
CISA KEV No
PoC Not public
References
External Resources
NVD Entry BleepingComputer The Hacker News