CVE-2020-26954

Name: CVE-2020-26954
Creator: NVD / NIST
Published: 2020-12-09T01:15:12.83+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.63%

Last modified Jun 17, 2026

CVE-2020-26954 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. EPSS estimates a 0.63% chance of exploitation in the next 30 days.

Description

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.63%

45.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 83.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1657026Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1657026Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-50/Vendor Advisory

Timeline

Published: Dec 9, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26954?

How severe is CVE-2020-26954?

CVE-2020-26954 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.63% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26954?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26954?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST