CVE-2026-2784: mozilla firefox
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-2784DEBIAN-CVE-2026-2784CGA-c326-p93p-g58wCGA-pp2v-qq8w-c87mCGA-63q7-5v98-gm77CGA-xq2v-88cj-vgh6
Published 24-02-2026Last modified 16-04-2026
Vulnerability summary
CVE-2026-2784 is a critical (CVSS 9.8) vulnerability in mozilla firefox. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 44.8% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.55%
0%100%
Low · +0.12 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 39 · Related 9DLA-4495-1DLA-4496-1DSA-6148-1DSA-6152-1MGASA-2026-0052MGASA-2026-0053OPENSUSE-SU-2026:10242-1OPENSUSE-SU-2026:10248-1OPENSUSE-SU-2026:10257-1OPENSUSE-SU-2026:20365-1OPENSUSE-SU-2026:20391-1RHSA-2026:3338RHSA-2026:3339RHSA-2026:3361RHSA-2026:3491RHSA-2026:3492RHSA-2026:3493RHSA-2026:3494RHSA-2026:3495RHSA-2026:3496RHSA-2026:3497RHSA-2026:3515RHSA-2026:3516RHSA-2026:3517RHSA-2026:3976RHSA-2026:3978RHSA-2026:3979RHSA-2026:3980RHSA-2026:3981RHSA-2026:3982RHSA-2026:3983RHSA-2026:3984RHSA-2026:4022RHSA-2026:4152RHSA-2026:4260RHSA-2026:4432SUSE-SU-2026:0812-1SUSE-SU-2026:0871-1SUSE-SU-2026:0880-1CGA-WFHM-VC8H-C672
Timeline
- 24-02-2026PublishedVulnerability first disclosed.
- 16-04-2026Last modifiedVulnerability information updated.
Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
CVSS metrics
6 scores · 6 sources · 1 versionCritical 9.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesAll 6 agree
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · WolfiEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.55%
Chance of exploitation in the next 30 days
Percentile
45%
Versus all other CVEs
30-day change
+0.12 pp
From 0.43% on 20-09-2026
20-09-202620-10-2026
EPSS score0.55%
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)
Chainguard2 products
- firefox< 140.8.0-r0
- firefox-esr< 140.8.0-r0
Debian2 products
- firefox-esr< 140.8.0esr-1~deb12u1 | < 140.8.0esr-1~deb13u1 | < 140.8.0esr-1
- thunderbird< 1:140.8.0esr-1~deb12u1 | < 1:140.8.0esr-1~deb13u1 | < 1:140.8.0esr-1
Mozilla2 products
- firefox< 140.8.0 | < 148.0
- thunderbird< 140.8.0 | < 148.0
Wolfi1 product
- firefox< 140.8.0-r0
5 vendors · 15 products
