VulnerabilityModified
CVE-2026-6754
Use-after-free in the JavaScript Engine component.
HIGH 7.5EPSS 0.39%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.39% probability · 33th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416, CWE-825
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2027541Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-30/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-31/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-32/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-33/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-34/Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:10757
- https://access.redhat.com/errata/RHSA-2026:10766
- https://access.redhat.com/errata/RHSA-2026:10767
- https://access.redhat.com/errata/RHSA-2026:12285
- https://access.redhat.com/errata/RHSA-2026:13537
- https://access.redhat.com/errata/RHSA-2026:15892
- https://access.redhat.com/errata/RHSA-2026:17477
- https://access.redhat.com/errata/RHSA-2026:17687
- https://access.redhat.com/errata/RHSA-2026:17688
- https://access.redhat.com/errata/RHSA-2026:17689
- https://access.redhat.com/errata/RHSA-2026:17690
- https://access.redhat.com/errata/RHSA-2026:19041
- https://access.redhat.com/errata/RHSA-2026:19131
- https://access.redhat.com/errata/RHSA-2026:19201
- https://access.redhat.com/errata/RHSA-2026:19348
- https://access.redhat.com/errata/RHSA-2026:19461
- https://access.redhat.com/errata/RHSA-2026:19462
- https://access.redhat.com/errata/RHSA-2026:19463
- https://access.redhat.com/errata/RHSA-2026:19464
- https://access.redhat.com/errata/RHSA-2026:19465
- https://access.redhat.com/errata/RHSA-2026:19466
- https://access.redhat.com/errata/RHSA-2026:19467
- https://access.redhat.com/errata/RHSA-2026:19468
- https://access.redhat.com/errata/RHSA-2026:19469
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.