Skip to content
Fencer Vulns
high 8.8

CVE-2026-100765 json

Use-after-free in the JavaScript: WebAssembly component

published 2026-09-29 40 d ago modified 2026-10-13 26 d ago also EUVD-2026-88917

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

Patch / fix

  • mozilla firefox 153.4, 157
  • mozilla firefox_esr 153.4, 157
  • mozilla thunderbird 153.4, 157
  • mozilla thunderbird_esr 153.4, 157
  • firefox-esr Debian 12 153.4.0esr-1~deb12u1
  • firefox-esr Debian 13 153.4.0esr-1~deb13u1
  • firefox-esr Debian 14 153.4.0esr-1
  • thunderbird Debian 14 1:153.4.0esr-1

debian advisories DEBIAN-CVE-2026-100765

  • MozillaThunderbird SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 153.4.0-150400.13.6.1
  • MozillaFirefox SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 153.4.0-150400.157.11.1
  • MozillaFirefox SLES for SAP applications 16.0, SLES 16.0 153.4.0-160000.1.1
  • MozillaFirefox SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 153.4.0-118.11.1

suse advisories SUSE-SU-2026:4627-1SUSE-SU-2026:4545-1SUSE-SU-2026:4543-1SUSE-SU-2026:23981-1

  • MozillaFirefox openSUSE Tumbleweed 157.0.1-1.1
  • MozillaThunderbird openSUSE Tumbleweed 153.4.0-1.1
  • MozillaFirefox openSUSE Leap 16.0 153.4.0-160000.1.1
  • firefox-esr openSUSE Tumbleweed 153.4.0-1.1

opensuse advisories openSUSE-SU-2026:12097-1openSUSE-SU-2026:12098-1openSUSE-SU-2026:21980-1openSUSE-SU-2026:11917-1

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-2026-100765 updated cvss 7.5

firefox: Use-after-free in the JavaScript: WebAssembly component

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

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
no
Technical impact
total
Assessed
41 d ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Mozilla Firefox
  • Mozilla Thunderbird

Classification

Weakness

References

Sources

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.