5.4

CVE-2026-100817: mozilla firefox

CVSS: 5.4v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-100817
Published 29-09-2026Last modified 01-10-2026
Open JSON

Vulnerability summary

CVE-2026-100817 is a medium (CVSS 5.4) vulnerability in mozilla firefox. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.9% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:12097-1

Timeline

  1. 29-09-2026
    PublishedVulnerability first disclosed.
  2. 01-10-2026
    Last modifiedVulnerability information updated.

Description

Other issue in the JavaScript: WebAssembly component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

30-09-202621-10-2026
EPSS score
0.20%

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

No weakness data has been published for this record.

Affected systems

Ubuntu8 products
  • mozjs102All versions (No fix recorded)
  • mozjs115All versions (No fix recorded)
  • mozjs38All versions (No fix recorded)
  • mozjs52All versions (No fix recorded)
  • mozjs68All versions (No fix recorded)
Mozilla2 products

2 vendors · 10 products

References

6 links