CVE-2020-26961: mozilla firefox
Vulnerability summary
CVE-2020-26961 is a medium (CVSS 6.5) vulnerability in mozilla firefox. EPSS estimates a 1.17% chance of exploitation in the next 30 days, higher than 66.8% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 33 · Related 15Timeline
- 09-12-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS trend
Probability
1.17%
Chance of exploitation in the next 30 days
Percentile
67%
Versus all other CVEs
30-day change
0.00 pp
From 1.17% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu5 products
- firefox< 83.0+build2-0ubuntu0.16.04.3 | < 83.0+build2-0ubuntu0.18.04.2 | < 83.0+build2-0ubuntu0.20.04.1
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- thunderbird< 1:78.8.1+build1-0ubuntu0.18.04.1 | < 1:78.7.1+build1-0ubuntu0.20.04.1
Mozilla3 products
- firefox< 83 | < 83.0
- firefox_esr< 78.5
- thunderbird< 78.5
Debian2 products
- firefox-esr< 78.5.0esr-1
- thunderbird< 1:78.5.0-1
3 vendors · 10 products
References
12 links- bugzilla.mozilla.org/show_bug.cgi?id=1672528X Refsource MISCIssue TrackingPermissions RequiredVendor Advisory
