CVE-2020-26977

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-01-07 · updated 2026-08-19

Description

By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. *Note: This issue only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84.

Affected products

Mozilla Firefox for Android: before 84.0 — fixed in 84.0

How to fix

Upgrade to a fixed version: Mozilla Firefox for Android 84.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1676311
https://www.mozilla.org/security/advisories/mfsa2020-54/
https://bugzilla.mozilla.org/show_bug.cgi?id=1676311
https://www.mozilla.org/security/advisories/mfsa2020-54/

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