PatchTheCVECVE-2023-34416: Memory safety bugs present in Firefox 113, Firefox ESR 102.11, and Thunderbird 102.12
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CRITICAL 9.8REMOTEUPGRADEUPGRADEUPGRADE
CVE-2023-34416 is a critical-severity flaw (CVSS 9.8) affecting firefox, firefox esr, thunderbird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Memory safety bugs present in Firefox 113, Firefox ESR 102.11, and Thunderbird 102.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 102.12, Firefox < 114, and Thunderbird < 102.12.
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.9% (top 40%) |
| CISA exploited list | No |
| Weakness | CWE-787 |
| Published | 2023-06-19 |
| Last modified | 2026-10-24 |
Publisher (CNA): Mozilla Corporation · Vendor: mozilla
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
mozilla firefox UPGRADE
Affected: < 114.0
Fixed in: 114.0
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy firefox || rpm -q firefox || firefox --version
2. UPGRADE to 114.0 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade firefox
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade firefox
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
mozilla firefox esr UPGRADE
Affected: < 102.12
Fixed in: 102.12
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy firefox-esr || rpm -q firefox-esr || firefox-esr --version
2. UPGRADE to 102.12 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade firefox-esr
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade firefox-esr
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
mozilla thunderbird UPGRADE
Affected: < 102.12
Fixed in: 102.12
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy thunderbird || rpm -q thunderbird || thunderbird --version
2. UPGRADE to 102.12 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade thunderbird
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade thunderbird
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
Exact fixes by distribution
Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source
sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321
Ubuntu 22.04 · firefox · NOT AFFECTED
Ubuntu 20.04 · firefox · FIXED · 114.0+build3-0ubuntu0.20.04.1
sudo apt update && sudo apt install --only-upgrade firefox
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "114.0+build3-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 24.04 · firefox · NOT AFFECTED
Ubuntu 22.04 · mozjs102 · FIXED · 102.12.0-0ubuntu0.22.04.1
sudo apt update && sudo apt install --only-upgrade mozjs102
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mozjs102)" ge "102.12.0-0ubuntu0.22.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 24.04 · mozjs102 · NOT AFFECTED
Debian 12 · firefox-esr · FIXED · 102.12.0esr-1~deb12u1
sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.12.0esr-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · firefox-esr · FIXED · 102.12.0esr-1
sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.12.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · thunderbird · FIXED · 1:102.12.0-1~deb12u1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.12.0-1~deb12u1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · thunderbird · FIXED · 1:102.12.0-1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.12.0-1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 7 · thunderbird · FIXED · thunderbird-102.12.0-1.el7_9
sudo dnf upgrade --advisory=RHSA-2023:3563
rpm -q thunderbird
RHEL 7 · firefox · FIXED · firefox-102.12.0-1.el7_9
sudo dnf upgrade --advisory=RHSA-2023:3579
rpm -q firefox
RHEL 8 · thunderbird · FIXED · thunderbird-102.12.0-1.el8_8
sudo dnf upgrade --advisory=RHSA-2023:3588
rpm -q thunderbird
RHEL 8 · firefox · FIXED · firefox-102.12.0-1.el8_8
sudo dnf upgrade --advisory=RHSA-2023:3590
rpm -q firefox
RHEL 8.1 Update Services for SAP Solutions · firefox · FIXED · firefox-102.12.0-1.el8_1
sudo dnf upgrade --advisory=RHSA-2023:3561
rpm -q firefox
Alpine 3.20 · firefox-esr · FIXED · firefox-esr-102.12.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.21 · firefox-esr · FIXED · firefox-esr-102.12.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.22 · firefox-esr · FIXED · firefox-esr-102.12.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.23 · firefox-esr · FIXED · firefox-esr-102.12.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2023-34416?
firefox: upgrade to 114.0; firefox esr: upgrade to 102.12; thunderbird: upgrade to 102.12. Exact commands for each OS are on this page.
Is CVE-2023-34416 being exploited?
CVE-2023-34416 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2023-34416 affect?
CVE-2023-34416 affects firefox, firefox esr, thunderbird. Severity is critical (CVSS 9.8). Memory safety bugs present in Firefox 113, Firefox ESR 102.11, and Thunderbird 102.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary c
How urgent is CVE-2023-34416?
Priority 54/100. Critical severity; Remotely exploitable, no login, no user action
Software pages
Mozilla Firefox vulnerabilities
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