CVE-2026-0884: mozilla firefox Use After Free
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-0884DEBIAN-CVE-2026-0884CGA-9xxq-425g-c9jmCGA-p5wh-gf4p-96mqCGA-r737-63fr-v498CGA-xgmj-r4rq-w8q4
Published 13-01-2026Last modified 13-04-2026
Vulnerability summary
CVE-2026-0884 is a critical (CVSS 9.8) Use After Free vulnerability in mozilla firefox. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.1% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · -0.01 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 38 · Related 11DLA-4439-1DLA-4442-1DSA-6101-1DSA-6103-1MGASA-2026-0013MGASA-2026-0014OPENSUSE-SU-2026:10037-1OPENSUSE-SU-2026:10046-1OPENSUSE-SU-2026:10058-1OPENSUSE-SU-2026:20041-1OPENSUSE-SU-2026:20391-1RHSA-2026:0667RHSA-2026:0694RHSA-2026:0924RHSA-2026:1320RHSA-2026:1413RHSA-2026:1414RHSA-2026:1415RHSA-2026:1461RHSA-2026:1462RHSA-2026:1471RHSA-2026:1487RHSA-2026:2041RHSA-2026:2043RHSA-2026:2044RHSA-2026:2047RHSA-2026:2069RHSA-2026:2070RHSA-2026:2073RHSA-2026:2074RHSA-2026:2220RHSA-2026:2231RHSA-2026:2271RHSA-2026:2286SUSE-SU-2026:0122-1SUSE-SU-2026:0153-1SUSE-SU-2026:0260-1SUSE-SU-2026:20086-1CGA-3PV7-J32J-MPFJUSN-7991-1
Timeline
- 13-01-2026PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
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
0.46%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
-0.01 pp
From 0.47% on 21-09-2026
21-09-202621-10-2026
EPSS score0.46%
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< 140.7-r0
- firefox-esr< 140.7-r0
Debian2 products
- firefox-esr< 140.7.0esr-1~deb12u1 | < 140.7.0esr-1~deb13u1 | < 140.7.0esr-1
- thunderbird< 1:140.7.0esr-1~deb12u1 | < 1:140.7.0esr-1~deb13u1 | < 1:140.7.0esr-1
Mozilla2 products
- firefox< 140.7.0 | < 147.0
- thunderbird< 140.7.0 | < 147.0
Wolfi1 product
- firefox< 140.7-r0
5 vendors · 15 products
