5.3

CVE-2026-6783: mozilla firefox Integer Overflow or Wraparound

CVSS: 5.3v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-6783CGA-gfjm-599x-jh4gCGA-q266-8mrc-7g3j
Published 21-04-2026Last modified 27-05-2026
Open JSON

Vulnerability summary

CVE-2026-6783 is a medium (CVSS 5.3) Integer Overflow or Wraparound vulnerability in mozilla firefox. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.7% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.38%
0%100%
Low · +0.15 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-2026:10626-1OPENSUSE-SU-2026:11373-1CGA-HMW9-G4HM-XJV7

Timeline

  1. 21-04-2026
    PublishedVulnerability first disclosed.
  2. 27-05-2026
    Last modifiedVulnerability information updated.

Description

Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

31%

Versus all other CVEs

30-day change

+0.15 pp

From 0.23% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.38%

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< 150-r0
Wolfi1 product
  • firefox< 150-r0

4 vendors · 12 products

References

6 links