7.5

CVE-2026-8964: mozilla firefox

CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-8964CGA-62q2-6f8m-w972CGA-hq2m-vgqc-qjf5
Published 19-05-2026Last modified 19-05-2026
Open JSON

Vulnerability summary

CVE-2026-8964 is a high (CVSS 7.5) vulnerability in mozilla firefox. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.9% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.39%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 3
OPENSUSE-SU-2026:10863-1OPENSUSE-SU-2026:11373-1CGA-XMXW-9GWC-H28P

Timeline

  1. 19-05-2026
    PublishedVulnerability first disclosed.
  2. 19-05-2026
    Last modifiedVulnerability information updated.

Description

Spoofing issue in the Popup Blocker component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

32%

Versus all other CVEs

30-day change

+0.09 pp

From 0.30% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.39%

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

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
Chainguard1 product
  • firefox< 151-r0
Wolfi1 product
  • firefox< 151-r0

4 vendors · 12 products

References

6 links