PatchTheCVECVE-2023-23605: Mozilla developers and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 108 and Firefox
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HIGH 8.8UPGRADEUPGRADEUPGRADE
CVE-2023-23605 is a high-severity flaw (CVSS 8.8) affecting firefox, firefox esr, thunderbird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Mozilla developers and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 108 and Firefox ESR 102.6. 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 < 109, Firefox ESR < 102.7, and Thunderbird < 102.7.
Why this priority
- High severity
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.7% (top 47%) |
| CISA exploited list | No |
| Weakness | CWE-787 |
| Published | 2023-06-02 |
| 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: < 109.0
Fixed in: 109.0
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy firefox || rpm -q firefox || firefox --version
2. UPGRADE to 109.0 (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: < 102.7
Fixed in: 102.7
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 102.7 (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: < 102.7
Fixed in: 102.7
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy thunderbird || rpm -q thunderbird || thunderbird --version
2. UPGRADE to 102.7 (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 · 109.0+build2-0ubuntu0.20.04.1
sudo apt update && sudo apt install --only-upgrade firefox
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "109.0+build2-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 24.04 · firefox · NOT AFFECTED
Ubuntu 20.04 · thunderbird · FIXED · 1:102.7.1+build2-0ubuntu0.20.04.1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.7.1+build2-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 22.04 · thunderbird · FIXED · 1:102.7.1+build2-0ubuntu0.22.04.1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.7.1+build2-0ubuntu0.22.04.1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · firefox-esr · FIXED · 102.7.0esr-1
sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.7.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · firefox-esr · FIXED · 102.7.0esr-1
sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.7.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · thunderbird · FIXED · 1:102.7.1-1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.7.1-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · thunderbird · FIXED · 1:102.7.1-1
sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.7.1-1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 7 · firefox · FIXED · firefox-102.7.0-1.el7_9
sudo dnf upgrade --advisory=RHSA-2023:0296
rpm -q firefox
RHEL 7 · thunderbird · FIXED · thunderbird-102.7.1-1.el7_9
sudo dnf upgrade --advisory=RHSA-2023:0456
rpm -q thunderbird
RHEL 8 · firefox · FIXED · firefox-102.7.0-1.el8_7
sudo dnf upgrade --advisory=RHSA-2023:0288
rpm -q firefox
RHEL 8 · thunderbird · FIXED · thunderbird-102.7.1-1.el8_7
sudo dnf upgrade --advisory=RHSA-2023:0463
rpm -q thunderbird
RHEL 8.1 Update Services for SAP Solutions · firefox · FIXED · firefox-102.7.0-1.el8_1
sudo dnf upgrade --advisory=RHSA-2023:0290
rpm -q firefox
Alpine 3.20 · firefox-esr · FIXED · firefox-esr-102.7.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.21 · firefox-esr · FIXED · firefox-esr-102.7.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.22 · firefox-esr · FIXED · firefox-esr-102.7.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.23 · firefox-esr · FIXED · firefox-esr-102.7.0-r0
apk add --upgrade firefox-esr
apk info -v firefox-esr
sudo yum update --advisory=ALAS2-2023-1951
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-2023-23605?
firefox: upgrade to 109.0; firefox esr: upgrade to 102.7; thunderbird: upgrade to 102.7. Exact commands for each OS are on this page.
Is CVE-2023-23605 being exploited?
CVE-2023-23605 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-2023-23605 affect?
CVE-2023-23605 affects firefox, firefox esr, thunderbird. Severity is high (CVSS 8.8). Mozilla developers and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 108 and Firefox ESR 102.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could hav
How urgent is CVE-2023-23605?
Priority 44/100. High severity
Software pages
Mozilla Firefox vulnerabilities
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