CVE-2026-8953: mozilla firefox Use After Free
CVSS: 9.6v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-8953DEBIAN-CVE-2026-8953CGA-2xcw-9265-4h5pCGA-pjc4-5fvr-f8wgCGA-22r6-9h95-62qwCGA-gjp5-3ffw-wxfq
Published 19-05-2026Last modified 22-07-2026
Vulnerability summary
CVE-2026-8953 is a critical (CVSS 9.6) Use After Free vulnerability in mozilla firefox. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.2% of scored vulnerabilities.
CVSS score
9.6/10
010
Critical · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · -0.08 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 27 · Related 5MGASA-2026-0164MGASA-2026-0165OPENSUSE-SU-2026:10813-1OPENSUSE-SU-2026:10863-1OPENSUSE-SU-2026:10864-1OPENSUSE-SU-2026:21168-1RHSA-2026:21378RHSA-2026:21380RHSA-2026:21381RHSA-2026:21382RHSA-2026:22325RHSA-2026:22643RHSA-2026:26174RHSA-2026:26268RHSA-2026:26269RHSA-2026:26270RHSA-2026:26491RHSA-2026:26492RHSA-2026:26493RHSA-2026:26521RHSA-2026:26536RHSA-2026:26539RHSA-2026:26551RHSA-2026:26606RHSA-2026:26629RHSA-2026:26630RHSA-2026:27715CGA-4FC2-QRQV-5WWM
Timeline
- 19-05-2026PublishedVulnerability first disclosed.
- 22-07-2026Last modifiedVulnerability information updated.
Description
Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
CVSS metrics
4 scores · 4 sources · 1 versionCritical 9.6Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated9.6CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.6CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- NVDNIST9.6CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
-0.08 pp
From 0.53% on 19-09-2026
19-09-202619-10-2026
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< 151.0.1-r0
- firefox-esr< 140.11.0-r0
Debian2 products
- firefox-esr< 140.11.0esr-1~deb12u1 | < 140.11.0esr-1~deb13u1 | < 140.11.0esr-1
- thunderbird< 1:140.11.0esr-1~deb12u1 | < 1:140.11.0esr-1~deb13u1 | < 1:140.11.0esr-1
Mozilla2 products
- firefox< 115.36.0 | < 151.0.0 | ≥ 140.0, < 140.11.0
- thunderbird< 140.11
Wolfi1 product
- firefox< 151.0.1-r0
5 vendors · 15 products
