CVE-2026-100763: mozilla firefox
CVSS: 9.1v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-100763
Published 29-09-2026Last modified 01-10-2026
Vulnerability summary
CVE-2026-100763 is a critical (CVSS 9.1) vulnerability in mozilla firefox. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.2% of scored vulnerabilities.
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)EPSS score
0.38%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 29-09-2026PublishedVulnerability first disclosed.
- 01-10-2026Last modifiedVulnerability information updated.
Description
Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.
CVSS metrics
3 scores · 3 sources · 1 versionCritical 9.1Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
30%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
30-09-202621-10-2026
EPSS score0.38%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected 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
- firefox< 157.0.0
- thunderbird< 157.0
2 vendors · 10 products
References
6 links- www.mozilla.org/security/advisories/mfsa2026-101/Vendor Advisory