CVE-2026-100782: mozilla firefox
CVSS: 8.8v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-100782DEBIAN-CVE-2026-100782
Published 29-09-2026Last modified 30-09-2026
Vulnerability summary
CVE-2026-100782 is a high (CVSS 8.8) vulnerability in mozilla firefox. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 16.4% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (CVE.org)EPSS score
0.26%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 10 · Related 8Timeline
- 29-09-2026PublishedVulnerability first disclosed.
- 30-09-2026Last modifiedVulnerability information updated.
Description
Privilege escalation due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
CVSS metrics
4 scores · 4 sources · 1 versionHigh 8.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.26%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
30-09-202619-10-2026
EPSS score0.26%
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)
Debian2 products
- firefox-esr< 153.4.0esr-1~deb12u1 | < 153.4.0esr-1~deb13u1 | < 153.4.0esr-1
- thunderbird< 1:140.17.0esr-1~deb12u1 | < 1:140.17.0esr-1~deb13u1 | < 1:153.4.0esr-1
Mozilla2 products
- firefox< 115.42.0 | ≥ 116.0, < 140.17.0 | ≥ 141.0, < 153.4.0 | ≥ 154.0.0, < 157.0.0
- thunderbird< 140.17.0 | ≥ 141.0, < 153.4.0 | ≥ 154.0, < 157.0
3 vendors · 12 products
References
13 links- www.mozilla.org/security/advisories/mfsa2026-101/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-102/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-103/Vendor Advisory