CVE-2026-6759 json
Use-after-free in the Widget: Cocoa component
published 2026-04-21 6 mo ago modified 2026-10-26 14 d ago also EUVD-2026-24100
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 30%
- public exploits
- 0
- none known
Summary
Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
Patch / fix
- mozilla firefox 140.10, 150
- mozilla firefox_esr 140.10, 150
- mozilla thunderbird 140.10, 150
- mozilla thunderbird_esr 140.10, 150
- thunderbird RHEL 9 140.10.1-1.el9_8
- firefox RHEL 9 140.10.0-1.el9_8
- firefox-x11 RHEL 9 140.10.0-1.el9_8
- thunderbird RHEL 10.2 140.10.0-1.el10_2
- firefox RHEL 10.2 140.10.0-1.el10_2
- thunderbird RHEL 9 140.10.0-1.el9_7
- thunderbird RHEL 8 140.10.0-1.el8_10
- thunderbird RHEL 10.1 140.10.0-1.el10_1
red hat advisories RHSA-2026:19704RHSA-2026:19655RHSA-2026:19542RHSA-2026:19469RHSA-2026:19467RHSA-2026:19468
- firefox-esr openSUSE Tumbleweed 153.0-1.1
- MozillaFirefox openSUSE Tumbleweed 150.0-1.1
- MozillaThunderbird openSUSE Tumbleweed 140.9.1-1.1
opensuse advisories openSUSE-SU-2026:11373-1openSUSE-SU-2026:10626-1openSUSE-SU-2026:10610-1
- thunderbird AlmaLinux 9 140.10.1-1.el9_8.alma.1
- thunderbird AlmaLinux 9 140.10.0-1.el9_7.alma.1
- thunderbird AlmaLinux 8 140.10.0-1.el8_10.alma.1
- thunderbird AlmaLinux 10 140.10.0-1.el10_1.alma.1
- firefox AlmaLinux 9 140.10.0-1.el9_7.alma.1
- firefox-x11 AlmaLinux 9 140.10.0-1.el9_7.alma.1
- firefox AlmaLinux 8 140.10.0-1.el8_10.alma.1
- firefox AlmaLinux 10 140.10.0-1.el10_1
almalinux advisories ALSA-2026:19348ALSA-2026:15892ALSA-2026:13537ALSA-2026:12285ALSA-2026:10757ALSA-2026:10766
- thunderbird Rocky Linux 9 140.10.1-1.el9_8
- firefox Rocky Linux 9 140.10.0-1.el9_7
- thunderbird Rocky Linux 9 140.10.0-1.el9_7
- thunderbird Rocky Linux 10 140.10.0-1.el10_1
- thunderbird Rocky Linux 8 140.10.0-1.el8_10
- firefox Rocky Linux 8 140.10.0-1.el8_10
- firefox Rocky Linux 10 140.10.0-1.el10_1
rocky linux advisories RLSA-2026:19348RLSA-2026:19201RLSA-2026:15892RLSA-2026:12285RLSA-2026:13537RLSA-2026:10766
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-6759 updated cvss 6.1
firefox: thunderbird: Use-after-free in the Widget: Cocoa component
-
Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 thunderbirdaffected: no fix planned “Out of support scope”
-
Red Hat Enterprise Linux 10 rhel10/firefox-flatpak, rhel10/thunderbird-flatpakaffected: no fix available
-
Red Hat Enterprise Linux AppStream (v. 8) firefox 140.10.0-1.el8_10, thunderbird 140.10.0-1.el8_10fixed: vendor fix RHSA-2026:10766
-
Red Hat Enterprise Linux AppStream (v. 9) firefox 140.10.0-1.el9_7, firefox 140.10.0-1.el9_8, firefox-x11 140.10.0-1.el9_7, firefox-x11 140.10.0-1.el9_8, thunderbird 140.10.0-1.el9_7, thunderbird 140.10.1-1.el9_8fixed: vendor fix RHSA-2026:10757
-
Red Hat Enterprise Linux AppStream (v. 10) firefox 140.10.0-1.el10_1, firefox 140.10.0-1.el10_2, thunderbird 140.10.0-1.el10_1, thunderbird 140.10.0-1.el10_2fixed: vendor fix RHSA-2026:10767
-
Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 140.10.0-1.el8_4, thunderbird 140.10.0-1.el8_4fixed: vendor fix RHSA-2026:19655
-
Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 140.10.0-1.el8_6, thunderbird 140.10.0-1.el8_6 Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox 140.10.0-1.el8_6, thunderbird 140.10.0-1.el8_6fixed: vendor fix RHSA-2026:19542
-
Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox 140.10.0-1.el8_8, thunderbird 140.10.0-1.el8_8fixed: vendor fix RHSA-2026:17477
show 9 moreshow fewer
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Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox 140.10.0-1.el9_0, thunderbird 140.10.0-1.el9_0fixed: vendor fix RHSA-2026:17687
-
Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox 140.10.0-1.el9_2, firefox-x11 140.10.0-1.el9_2, thunderbird 140.10.0-1.el9_2fixed: vendor fix RHSA-2026:17689
-
Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox 140.10.0-1.el10_0, thunderbird 140.10.0-1.el10_0fixed: vendor fix RHSA-2026:17690
-
Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox 140.10.0-1.el9_4, firefox-x11 140.10.0-1.el9_4, thunderbird 140.10.0-1.el9_4fixed: vendor fix RHSA-2026:19464
-
Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox 140.10.0-1.el9_6, firefox-x11 140.10.0-1.el9_6, thunderbird 140.10.0-1.el9_6fixed: vendor fix RHSA-2026:17688
-
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox 140.10.0-1.el8_4, thunderbird 140.10.0-1.el8_4fixed: vendor fix RHSA-2026:19655
-
Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox 140.10.0-1.el8_6, thunderbird 140.10.0-1.el8_6fixed: vendor fix RHSA-2026:19542
-
Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox 140.10.0-1.el8_8, thunderbird 140.10.0-1.el8_8fixed: vendor fix RHSA-2026:17477
-
Red Hat Enterprise Linux Server (v. 7 ELS) firefox 140.10.0-2.el7_9fixed: vendor fix RHSA-2026:19704
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
- Mozilla Firefox
- Mozilla Thunderbird
Classification
- Weakness
-
- CWE-416 Use After Free
References
-
mozilla.org
/security/advisories/mfsa2026-30/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2026-32/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2026-33/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2026-34/
vendor-advisory
-
bugzilla.mozilla.org
/show_bug.cgi?id=2016164
permissions-required
Sources
- CVE List CVE-2026-6759
- NVD CVE-2026-6759
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.