What’s Vulnerable › Vulnerabilities

CVE-2026-8090: Use-after-free in the DOM: Networking component

• Severity: high (CVSS 7.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-07 · updated 2026-10-26
• Weakness: CWE-416

Description

Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2.

Affected products

• Mozilla Firefox: before 115.35.2; before 150.0.2; from 128.0 before 140.10.2 — fixed in 115.35.2, 150.0.2, 140.10.2
• Mozilla Thunderbird: before 140.10.2; before 150.0.2 — fixed in 140.10.2, 150.0.2

How to fix

Upgrade to a fixed version: Mozilla Firefox 115.35.2, 150.0.2, 140.10.2; Mozilla Thunderbird 140.10.2, 150.0.2. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2034352
• https://www.mozilla.org/security/advisories/mfsa2026-40/
• https://www.mozilla.org/security/advisories/mfsa2026-41/
• https://www.mozilla.org/security/advisories/mfsa2026-42/
• https://www.mozilla.org/security/advisories/mfsa2026-43/
• https://www.mozilla.org/security/advisories/mfsa2026-44/
• https://access.redhat.com/errata/RHSA-2026:19160
• https://access.redhat.com/errata/RHSA-2026:20566
• https://access.redhat.com/errata/RHSA-2026:20574
• https://access.redhat.com/errata/RHSA-2026:21381
• https://access.redhat.com/errata/RHSA-2026:22325
• https://access.redhat.com/errata/RHSA-2026:22643

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