9.3

CVE-2020-26960: mozilla firefox Use After Free

CVSS: 9.3v2.0HighModified
AliasesUBUNTU-CVE-2020-26960DEBIAN-CVE-2020-26960
Published 09-12-2020Last modified 04-08-2024

Vulnerability summary

CVE-2020-26960 is a high (CVSS 9.3) Use After Free vulnerability in mozilla firefox. EPSS estimates a 1.56% chance of exploitation in the next 30 days, higher than 74.9% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
High · v2.0 (NVD)
EPSS score
1.56%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 33 · Related 15

Timeline

  1. 09-12-2020
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

If the Compact() method was called on an nsTArray, the array could have been reallocated without updating other pointers, leading to a potential use-after-free and exploitable crash. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.56%

Chance of exploitation in the next 30 days

Percentile

75%

Versus all other CVEs

30-day change

0.00 pp

From 1.56% on 19-09-2026

19-09-202619-10-2026
EPSS score
1.56%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

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
Debian2 products
  • firefox-esr< 78.5.0esr-1
  • thunderbird< 1:78.5.0-1

3 vendors · 10 products

References

12 links
Show all 12 references