CVE-2026-12293: mozilla firefox Use After Free
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-12293CGA-hj6w-mq3v-rvvmCGA-wmfx-mxwh-pxff
Published 16-06-2026Last modified 15-07-2026
Vulnerability summary
CVE-2026-12293 is a critical (CVSS 9.8) Use After Free vulnerability in mozilla firefox. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.7% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.30%
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 2 · Related 3Timeline
- 16-06-2026PublishedVulnerability first disclosed.
- 15-07-2026Last modifiedVulnerability information updated.
Description
Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.
CVSS metrics
3 scores · 3 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 3 agree
- OSV · UbuntuEcosystem 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
0.30%
Chance of exploitation in the next 30 days
Percentile
22%
Versus all other CVEs
30-day change
0.00 pp
From 0.30% on 21-09-2026
21-09-202621-10-2026
EPSS score0.30%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-825Expired Pointer DereferenceThe product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Affected 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)
Mozilla2 products
- firefox< 152.0.0
- thunderbird< 152.0.0
Chainguard1 product
- firefox< 152-r0
Wolfi1 product
- firefox< 152-r0
4 vendors · 12 products
References
9 links- bugzilla.mozilla.org/show_bug.cgi?id=2039568Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-57/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-60/Vendor Advisory