CVE-2026-4724: Undefined behavior in the Audio/Video component
Vulnerability summary
CVE-2026-4724 is a critical (CVSS 9.1) vulnerability in mozilla firefox. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 43.2% of scored vulnerabilities.
Severe, CVSS 9.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 2 · Related 3Timeline
- 24-03-2026PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Undefined behavior in the Audio/Video component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS trend
Probability
0.51%
Chance of exploitation in the next 30 days
Percentile
43%
Versus all other CVEs
30-day change
Increase +0.08 pp
From 0.43% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
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
- firefox< 149.0
- thunderbird< 149.0
Chainguard1 product
- firefox< 149.0-r0
Wolfi1 product
- firefox< 149.0-r0
4 vendors · 12 products