CVSS 3.1
8.8 highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCVE-2026-124862 mozilla: Use After Free
High (8.8) in mozilla. EPSS 0.4% estimated probability of exploitation activity in the next 30 days.
On this page
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
Severity
- EPSS
- 0.4% estimated probability of exploitation activity in the next 30 days; 33rd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-10. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-416 Use After Free
- Published
- Modified
- Assigned by
- mozilla (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-124862 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-124862?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-124862?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-124862 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-124862)
HTML:
<a href="https://cve.bz/cve/CVE-2026-124862"><img src="https://cve.bz/cve/badge/CVE-2026-124862.svg" alt="CVE-2026-124862"></a>
Affected
Versions
From the CNA's record in the CVE List.
Fixed in
| Product | Release line | Fixed in |
|---|---|---|
| Mozilla Firefox | 153 | 153.7 |
| Mozilla Firefox | later releases | 160 |
| Mozilla Thunderbird | 153 | 153.7 |
| Mozilla Thunderbird | later releases | 160 |
Fix and patched versions
- Mozilla Firefox: fixed in 153.7
- Mozilla Firefox: fixed in 160
- Mozilla Thunderbird: fixed in 153.7
- Mozilla Thunderbird: fixed in 160
- Debian, Red Hat, SUSE, openSUSE, AlmaLinux, Rocky Linux: fixed package versions per release
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12 | firefox-esr | 153.7.0esr-1~deb12u1 | DEBIAN-CVE-2026-124862 |
| Debian | 12 | thunderbird | 1:153.7.0esr-1~deb12u1 | DEBIAN-CVE-2026-124862 |
| Debian | 13 | firefox-esr | 153.7.0esr-1~deb13u1 | DEBIAN-CVE-2026-124862 |
| Debian | 13 | thunderbird | 1:153.7.0esr-1~deb13u1 | DEBIAN-CVE-2026-124862 |
| Debian | 14 | firefox-esr, thunderbird | no fix listed | DEBIAN-CVE-2026-124862 |
| Ubuntu | 18.04:LTS | mozjs38, mozjs52 | no fix listed | UBUNTU-CVE-2026-124862 |
| Ubuntu | 20.04:LTS | mozjs52, mozjs68 | no fix listed | UBUNTU-CVE-2026-124862 |
| Ubuntu | 22.04:LTS | mozjs78, mozjs91, mozjs102 and 1 more | no fix listed | UBUNTU-CVE-2026-124862 |
| Ubuntu | 24.04:LTS | mozjs102, mozjs115 | no fix listed | UBUNTU-CVE-2026-124862 |
| Red Hat | enterprise_linux:8::appstream | firefox, firefox-debuginfo, firefox-debugsource | 0:153.7.0-1.el8_10 | RHSA-2026:99112 |
| Red Hat | enterprise_linux:9::appstream | firefox, firefox-x11, firefox-debuginfo and 1 more | 0:153.7.0-1.el9_9 | RHSA-2026:99111 |
| Red Hat | enterprise_linux:10.3 | firefox, firefox-debuginfo, firefox-debugsource | 0:153.7.0-1.el10_3 | RHSA-2026:99572 |
| Red Hat | enterprise_linux_eus:10.2 | firefox, firefox-debuginfo, firefox-debugsource | 0:153.7.0-1.el10_2 | RHSA-2026:99571 |
| Red Hat | rhel_eus:9.8::appstream | firefox, firefox-x11, firefox-debuginfo and 1 more | 0:153.7.0-1.el9_8 | RHSA-2026:99110 |
| SUSE | Linux Enterprise High Performance Computing 15 SP4-ESPOS, Linux Enterprise High Performance Computing 15 SP4-LTSS, Linux Enterprise High Performance Computing 15 SP5-ESPOS and 8 more | MozillaFirefox | 153.7.0-150400.157.22.1 | SUSE-SU-2026:5229-1 |
| SUSE | Linux Enterprise Server 12 SP5-LTSS, Linux Enterprise Server LTSS Extended Security 12 SP5 | MozillaFirefox | 153.7.0-118.22.1 | SUSE-SU-2026:5174-1 |
| openSUSE | Tumbleweed | firefox-esr | 153.7.0-1.1 | openSUSE-SU-2026:12527-1 |
| AlmaLinux | 8 | firefox | 153.7.0-1.el8_10 | ALSA-2026:99112 |
| Rocky Linux | 8 | firefox, firefox-debuginfo, firefox-debugsource | 0:153.7.0-1.el8_10 | RLSA-2026:99112 |
| Rocky Linux | 9 | firefox, firefox-x11, firefox-debuginfo and 1 more | 0:153.7.0-1.el9_9 | RLSA-2026:99111 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; SUSE security data, CC BY 4.0; AlmaLinux's OSV database, MIT; Rocky Linux's errata, BSD-3-Clause. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat · SUSE · openSUSE.
Red Hat
Red Hat rates this Important.
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Avoid navigating to untrusted websites in Firefox and exercise caution with untrusted HTML emails or unsolicited attachments in Thunderbird. Where application usage is required, isolate browser and mail sessions within a sandboxed environment (such as an unprivileged container or Flatpak sandbox) to constrain potential access to host resources.
If graphical web browsing or email processing is not required on the system, remove the affected packages:
```
dnf remove firefox thunderbird
```
Caveat: On graphical desktop installations, removing these packages may remove dependent desktop components or alter desktop environment functionality. Headless or terminal-based server environments will remain unaffected.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | firefox-0:153.7.0-1.el8_10 | Fixed 2026-11-11 | RHSA-2026:99112 |
| Red Hat Enterprise Linux 9 | firefox-0:153.7.0-1.el9_9 | Fixed 2026-11-11 | RHSA-2026:99111 |
| Red Hat Enterprise Linux 9.8 Extended Update Support | firefox-0:153.7.0-1.el9_8 | Fixed 2026-11-11 | RHSA-2026:99110 |
| Red Hat Enterprise Linux 10 | firefox | Affected | |
| Red Hat Enterprise Linux 10 | rhel10/firefox-flatpak | Affected | |
| Red Hat Enterprise Linux 10 | rhel10/thunderbird-flatpak | Affected | |
| Red Hat Enterprise Linux 10 | thunderbird | Affected | |
| Red Hat Enterprise Linux 6 | firefox | Out of support scope | |
| Red Hat Enterprise Linux 6 | thunderbird | Out of support scope | |
| Red Hat Enterprise Linux 7 | firefox | Affected | |
| Red Hat Enterprise Linux 7 | thunderbird | Out of support scope | |
| Red Hat Enterprise Linux 8 | thunderbird | Affected | |
| Red Hat Enterprise Linux 9 | thunderbird | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-124862.
History
- Scored 8.8 high
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.