CVE-2025-1012: mozilla firefox Use After Free
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2025-1012DEBIAN-CVE-2025-1012CGA-6qgr-qchc-9vwwCGA-fgxh-948m-3vqxCGA-5mxm-7v8f-cv3vCGA-5xqp-xx9r-cmmq
Published 04-02-2025Last modified 13-04-2026
Vulnerability summary
CVE-2025-1012 is a critical (CVSS 9.8) Use After Free vulnerability in mozilla firefox. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.9% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.45%
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 33 · Related 10DLA-4044-1DLA-4045-1DSA-5858-1DSA-5861-1MGASA-2025-0045MGASA-2025-0048OPENSUSE-SU-2025:14727-1OPENSUSE-SU-2025:14730-1OPENSUSE-SU-2025:14731-1RHSA-2025:1066RHSA-2025:1132RHSA-2025:1133RHSA-2025:1135RHSA-2025:1136RHSA-2025:1137RHSA-2025:1138RHSA-2025:1139RHSA-2025:1140RHSA-2025:1184RHSA-2025:1283RHSA-2025:1292RHSA-2025:1317RHSA-2025:1318RHSA-2025:1319RHSA-2025:1339RHSA-2025:1340RHSA-2025:1341RHSA-2025:1348SUSE-SU-2025:0374-1SUSE-SU-2025:0391-1SUSE-SU-2025:0405-1USN-7263-1USN-7663-1CGA-3C4M-HRG9-W3HHCGA-6HM8-2GGH-87H4
Timeline
- 04-02-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
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:HSources6 sources · 7.5–9.8
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · WolfiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
0.00 pp
From 0.45% on 19-09-2026
19-09-202619-10-2026
EPSS score0.45%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu9 products
- firefox< 135.0+build2-0ubuntu0.20.04.1
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
Chainguard2 products
- firefox< 135.0-r0
- firefox-esr< 128.7.0-r0
Debian2 products
- firefox-esr< 128.7.0esr-1~deb12u1 | < 128.7.0esr-1
- thunderbird< 1:128.7.0esr-1~deb12u1 | < 1:128.7.0esr-1
Mozilla2 products
- firefox< 115.20.0 | < 135.0 | ≥ 128.1.0, < 128.7.0
- thunderbird< 135.0 | ≥ 128.0.1, < 128.7.0
Wolfi1 product
- firefox< 135.0-r0
5 vendors · 16 products
