6.5

CVE-2026-100793: JIT miscompilation in the JavaScript Engine component

Analyzed
AliasesUBUNTU-CVE-2026-100793
Published 29-09-2026Last modified 01-10-2026

Vulnerability summary

CVE-2026-100793 is a medium (CVSS 6.5) Type Confusion vulnerability in mozilla firefox. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.27%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware 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

JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

30-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

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