CVE-2020-15655

6.5 mediumEPSS 1.5%

Medium (6.5). EPSS 1.5% chance of exploitation in the next 30 days.

A redirected HTTP request which is observed or modified through a web extension could bypass existing CORS checks, leading to potential disclosure of cross-origin information. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Severity

CVSS 3.1

6.5 medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS: 1.5% chance of exploitation in the next 30 days; higher than 74% of CVEs (scores of 2026-10-31)
Published: 2020-08-10
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

canonical:ubuntu_linux
mozilla:firefox
mozilla:firefox_esr
mozilla:thunderbird
opensuse:leap

References

http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1645204
https://usn.ubuntu.com/4443-1/
https://www.mozilla.org/security/advisories/mfsa2020-30/
https://www.mozilla.org/security/advisories/mfsa2020-32/

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