CVE-2026-16392: mozilla firefox
CVSS: 9.1v3.1CriticalAnalyzed
AliasesUBUNTU-CVE-2026-16392CGA-g9gq-w5j6-q2fxCGA-h5cr-v255-wrr7CGA-mxv6-gpv9-p82qCGA-wv82-9rw8-gwrvCGA-66g2-rf8j-m8v5CGA-8j25-53h4-hv59
Published 21-07-2026Last modified 28-07-2026
Vulnerability summary
CVE-2026-16392 is a critical (CVSS 9.1) vulnerability in mozilla firefox. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.7% of scored vulnerabilities.
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)EPSS score
0.36%
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.
- 28-07-2026Last modifiedVulnerability information updated.
Description
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS metrics
3 scores · 3 sources · 1 versionCritical 9.1Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- NVDNIST9.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS trend
Probability
0.36%
Chance of exploitation in the next 30 days
Percentile
29%
Versus all other CVEs
30-day change
0.00 pp
From 0.36% on 21-09-2026
21-09-202621-10-2026
EPSS score0.36%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-670Always-Incorrect Control Flow ImplementationThe code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.
- CWE-843Access of Resource Using Incompatible Type ('Type Confusion')The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
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)
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=2044606Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-71/Vendor Advisory