CVE-2025-8036

moderate-risk

Published 2025-07-22

Thunderbird cached CORS preflight responses across IP address changes. This allowed circumventing CORS with DNS rebinding. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.

Do I need to act?

0.07% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 8.1/10 High

NETWORK / LOW complexity

Affected Products (4)

Firefox

Thunderbird

Affected Vendors

Mozilla

References (6)

Permissions Required https://bugzilla.mozilla.org/show_bug.cgi?id=1960834

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-56/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-59/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-61/

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2025-63/

https://www.kb.cert.org/vuls/id/652514

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moderate-risk

Severity 28/34 · Critical

Exploitability 0/34 · Minimal

Exposure 10/34 · Low