CVE-2025-14321: mozilla firefox Use After Free
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2025-14321DEBIAN-CVE-2025-14321CGA-2g9g-94rw-r57jCGA-p8c3-6873-jrxxCGA-4jjw-9w6f-244vCGA-rwmc-4qrh-72cc
Published 09-12-2025Last modified 13-04-2026
Vulnerability summary
CVE-2025-14321 is a critical (CVSS 9.8) Use After Free vulnerability in mozilla firefox. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.4% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.60%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 40 · Related 11DLA-4401-1DLA-4405-1DSA-6078-1DSA-6081-1MGASA-2025-0328MGASA-2025-0329OPENSUSE-SU-2025:15809-1OPENSUSE-SU-2025:15813-1OPENSUSE-SU-2025:15814-1OPENSUSE-SU-2026:20014-1OPENSUSE-SU-2026:20046-1RHSA-2025:23034RHSA-2025:23035RHSA-2025:23128RHSA-2025:23856RHSA-2026:0003RHSA-2026:0004RHSA-2026:0005RHSA-2026:0006RHSA-2026:0007RHSA-2026:0013RHSA-2026:0014RHSA-2026:0015RHSA-2026:0016RHSA-2026:0017RHSA-2026:0018RHSA-2026:0019RHSA-2026:0020RHSA-2026:0021RHSA-2026:0022RHSA-2026:0023RHSA-2026:0024RHSA-2026:0025RHSA-2026:0026RHSA-2026:0124RHSA-2026:0127SUSE-SU-2025:4396-1SUSE-SU-2025:4397-1SUSE-SU-2025:4424-1SUSE-SU-2026:20031-1CGA-MPRJ-GVJP-VHJ7USN-7991-1
Timeline
- 09-12-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Use-after-free in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.
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
0.60%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
0.00 pp
From 0.60% on 19-09-2026
19-09-202619-10-2026
EPSS score0.60%
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< 140.6-r0
- firefox-esr< 140.6-r0
Debian2 products
- firefox-esr< 140.6.0esr-1~deb12u1 | < 140.6.0esr-1~deb13u1 | < 140.6.0esr-1
- thunderbird< 1:140.6.0esr-1~deb12u1 | < 1:140.6.0esr-1~deb13u1 | < 1:140.6.0esr-1
Mozilla2 products
- firefox< 140.6.0 | < 146.0
- thunderbird< 140.6.0 | < 146.0
Wolfi1 product
- firefox< 140.6-r0
5 vendors · 15 products
