CVE-2020-26979

Name: CVE-2020-26979
Creator: NVD / NIST
Published: 2021-01-07T14:15:12.377+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.72%

Last modified Jun 17, 2026

CVE-2020-26979 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. When a user typed a URL in the address bar or the search bar and quickly hit the enter key, a website could sometimes capture that event and then redirect the user before navigation occurred to the desired, entered address. To construct a convincing spoof the attacker would have had to guess what the user was typing, perhaps by suggesting it. EPSS estimates a 0.72% chance of exploitation in the next 30 days.

Description

When a user typed a URL in the address bar or the search bar and quickly hit the enter key, a website could sometimes capture that event and then redirect the user before navigation occurred to the desired, entered address. To construct a convincing spoof the attacker would have had to guess what the user was typing, perhaps by suggesting it. This vulnerability affects Firefox < 84.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.72%

49.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 84.0

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1641287%2C1673299Exploit, Issue Tracking, Patch, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1641287%2C1673299Exploit, Issue Tracking, Patch, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory

Timeline

Published: Jan 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26979?

How severe is CVE-2020-26979?

CVE-2020-26979 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26979?

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-2020-26979?

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

Scan your code now

Source: NVD / NIST