CVE-2026-117862
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AI Threat Summary
CVE-2026-117862 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 incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
Attack Chain
Attacker has low-privilege local access (e.g., via phishing or compromised service account)
Attacker exploits CVE-2026-117862 to escalate from low-privilege user to root/SYSTEM/admin
Elevated privileges used to disable security controls, clear logs, and establish persistence
Full system compromise achieved; attacker can install ransomware, exfiltrate all data, or pivot
MITRE ATT&CK Techniques
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
Quick Facts
| CVE ID | CVE-2026-117862 |
| CVSS Score | N/A |
| Published | 2026-10-27 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2054644
- https://www.mozilla.org/security/advisories/mfsa2026-118/
- https://www.mozilla.org/security/advisories/mfsa2026-119/
- https://www.mozilla.org/security/advisories/mfsa2026-120/
- https://www.mozilla.org/security/advisories/mfsa2026-121/
- https://www.mozilla.org/security/advisories/mfsa2026-122/