CVE-2020-26974: mozilla firefox Out-of-bounds Write
CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2020-26974DEBIAN-CVE-2020-26974
Published 07-01-2021Last modified 04-08-2024
Vulnerability summary
CVE-2020-26974 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 1.53% chance of exploitation in the next 30 days, higher than 74.4% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (NVD)EPSS score
1.53%
0%100%
Low · +0.02 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 30 · Related 14DLA-2496-1DLA-2497-1DSA-4813-1DSA-4815-1MGASA-2020-0461MGASA-2020-0462OPENSUSE-SU-2020:2317-1OPENSUSE-SU-2020:2318-1OPENSUSE-SU-2020:2324-1OPENSUSE-SU-2020:2325-1OPENSUSE-SU-2024:10600-1OPENSUSE-SU-2024:10601-1OPENSUSE-SU-2024:14572-1RHSA-2020:5561RHSA-2020:5562RHSA-2020:5563RHSA-2020:5564RHSA-2020:5565RHSA-2020:5618RHSA-2020:5622RHSA-2020:5624RHSA-2020:5644RHSA-2020:5645SUSE-SU-2020:14584-1SUSE-SU-2020:3900-1SUSE-SU-2020:3901-1SUSE-SU-2020:3902-1SUSE-SU-2020:3903-1SUSE-SU-2020:3935-1USN-4671-1
Timeline
- 07-01-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.
CVSS metrics
4 scores · 3 sources · 2 versionsHigh 8.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Medium 6.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
1.53%
Chance of exploitation in the next 30 days
Percentile
74%
Versus all other CVEs
30-day change
+0.02 pp
From 1.52% on 19-09-2026
19-09-202619-10-2026
EPSS score1.53%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu6 products
- firefox< 84.0+build3-0ubuntu0.16.04.1 | < 84.0+build3-0ubuntu0.18.04.1 | < 84.0+build3-0ubuntu0.20.04.1
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- mozjs78All versions (No fix recorded)
Mozilla3 products
- firefox≥ unspecified, < 84 | < 84.0
- firefox_esr≥ unspecified, < 78.6 | < 78.6.0
- thunderbird≥ unspecified, < 78.6 | < 78.6.0
Debian2 products
- firefox-esr< 78.6.0esr-1
- thunderbird< 1:78.6.0-1
3 vendors · 11 products
