CVE-2026-16386: mozilla firefox Use of Uninitialized Resource
CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-16386CGA-84h4-h8rc-rgv6CGA-c7ff-54pf-gf7qCGA-r78g-2222-mm6mCGA-whv2-9wrj-7743CGA-gxxr-hjh7-5c27CGA-q27x-xqqg-p7pw
Published 21-07-2026Last modified 22-07-2026
Vulnerability summary
CVE-2026-16386 is a high (CVSS 7.5) Use of Uninitialized Resource vulnerability in mozilla firefox. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.7% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.31%
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 8 · Related 9Timeline
- 21-07-2026PublishedVulnerability first disclosed.
- 22-07-2026Last modifiedVulnerability information updated.
Description
Information disclosure due to uninitialized memory in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS metrics
3 scores · 3 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.31%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
0.00 pp
From 0.31% on 21-09-2026
21-09-202621-10-2026
EPSS score0.31%
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)
Chainguard3 products
- firefox< 153.0-r0
- firefox-docker-selenium-compat< 153.0-r0
- firefox-esr-140< 140.14.0-r0
Mozilla2 products
- firefox< 153.0.0
- thunderbird< 153.0
Wolfi2 products
- firefox< 153.0-r0
- firefox-docker-selenium-compat< 153.0-r0
4 vendors · 15 products
References
6 links- bugzilla.mozilla.org/show_bug.cgi?id=2041916Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-71/Vendor Advisory