9.3

CVE-2020-12426: mozilla firefox Out-of-bounds Write

CVSS: 9.3v2.0HighModified
AliasesUBUNTU-CVE-2020-12426
Published 09-07-2020Last modified 04-08-2024

Vulnerability summary

CVE-2020-12426 is a high (CVSS 9.3) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 1.61% chance of exploitation in the next 30 days, higher than 75.5% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
High · v2.0 (NVD)
EPSS score
1.61%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Advisory lineage

Upstream 0 · Downstream 9 · Related 8

Timeline

  1. 09-07-2020
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

Mozilla developers and community members reported memory safety bugs present in Firefox 77. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 78.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

1.61%

Chance of exploitation in the next 30 days

Percentile

76%

Versus all other CVEs

30-day change

-0.01 pp

From 1.62% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.61%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (bugzilla.mozilla.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Ubuntu5 products
  • firefox< 78.0.1+build1-0ubuntu0.16.04.1 | < 78.0.1+build1-0ubuntu0.18.04.1 | < 78.0.1+build1-0ubuntu0.20.04.1
  • 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
Mozilla1 product
  • firefox≥ unspecified, < 78 | < 78.0
Opensuse1 product

3 vendors · 7 products

References

10 links