What’s Vulnerable › Vulnerabilities

CVE-2026-6761: Privilege escalation in the Networking component

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-21 · updated 2026-10-26
• Weakness: CWE-269

Description

Privilege escalation in the Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Affected products

• Mozilla Firefox: before 140.10.0; before 150.0 — fixed in 140.10.0, 150.0
• Mozilla Thunderbird: before 140.10.0 — fixed in 140.10.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 140.10.0, 150.0; Mozilla Thunderbird 140.10.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2017857
• https://www.mozilla.org/security/advisories/mfsa2026-30/
• https://www.mozilla.org/security/advisories/mfsa2026-32/
• https://www.mozilla.org/security/advisories/mfsa2026-33/
• https://www.mozilla.org/security/advisories/mfsa2026-34/

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