CVE-2023-28176: Memory safety bugs present in Firefox 110 and Firefox ESR 102.8 HIGH 8.8 UPGRADE UPGRADE UPGRADE
CVE-2023-28176 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.
Memory safety bugs present in Firefox 110 and Firefox ESR 102.8. 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 < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.
Why this priority 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
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline 2023-06-02 17:15 UTC Published CVE record published2026-10-24 13:10 UTC Updated Record last modifiedmozilla firefox UPGRADE
Affected: < 111.0
Fixed in: 111.0
Safe to downgrade to: no unaffected older release
1. Check installed version
Copy apt-cache policy firefox || rpm -q firefox || firefox --version
2. UPGRADE to 111.0 (Debian / Ubuntu)
Copy sudo apt update && sudo apt install --only-upgrade firefox
2. UPGRADE (RHEL / Amazon Linux / Fedora)
Copy sudo dnf upgrade firefox
Note
Copy Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
mozilla firefox esr UPGRADE
Affected: < 102.9
Fixed in: 102.9
Safe to downgrade to: no unaffected older release
1. Check installed version
Copy apt-cache policy firefox-esr || rpm -q firefox-esr || firefox-esr --version
2. UPGRADE to 102.9 (Debian / Ubuntu)
Copy sudo apt update && sudo apt install --only-upgrade firefox-esr
2. UPGRADE (RHEL / Amazon Linux / Fedora)
Copy sudo dnf upgrade firefox-esr
Note
Copy Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
mozilla thunderbird UPGRADE
Affected: < 102.9
Fixed in: 102.9
Safe to downgrade to: no unaffected older release
1. Check installed version
Copy apt-cache policy thunderbird || rpm -q thunderbird || thunderbird --version
2. UPGRADE to 102.9 (Debian / Ubuntu)
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
2. UPGRADE (RHEL / Amazon Linux / Fedora)
Copy sudo dnf upgrade thunderbird
Note
Copy Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
Exact fixes by distribution Show all
Fedora 46 · gnome-shell-extension-tiling-assistant ·
FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 ·
source Copy sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321
Ubuntu 22.04 · firefox · NOT AFFECTED
Ubuntu 20.04 · firefox · FIXED · 111.0+build2-0ubuntu0.20.04.1
Copy sudo apt update && sudo apt install --only-upgrade firefox
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "111.0+build2-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 24.04 · firefox · NOT AFFECTED
Ubuntu 20.04 · thunderbird · FIXED · 1:102.9.0+build1-0ubuntu0.20.04.1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.9.0+build1-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 22.04 · thunderbird · FIXED · 1:102.9.0+build1-0ubuntu0.22.04.1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.9.0+build1-0ubuntu0.22.04.1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · firefox-esr · FIXED · 102.9.0esr-1
Copy sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.9.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · firefox-esr · FIXED · 102.9.0esr-1
Copy sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.9.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · thunderbird · FIXED · 1:102.9.0-1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.9.0-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · thunderbird · FIXED · 1:102.9.0-1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.9.0-1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 7 · firefox · FIXED · firefox-102.9.0-3.el7_9
Copy sudo dnf upgrade --advisory=RHSA-2023:1333
rpm -q firefox
RHEL 7 · thunderbird · FIXED · thunderbird-102.9.0-1.el7_9
Copy sudo dnf upgrade --advisory=RHSA-2023:1401
rpm -q thunderbird
RHEL 8 · firefox · FIXED · firefox-102.9.0-3.el8_7
Copy sudo dnf upgrade --advisory=RHSA-2023:1336
rpm -q firefox
RHEL 8 · thunderbird · FIXED · thunderbird-102.9.0-1.el8_7
Copy sudo dnf upgrade --advisory=RHSA-2023:1403
rpm -q thunderbird
RHEL 8.1 Update Services for SAP Solutions · thunderbird · FIXED · thunderbird-102.9.0-2.el8_1
Copy sudo dnf upgrade --advisory=RHSA-2023:1442
rpm -q thunderbird
Alpine 3.20 · firefox-esr · FIXED · firefox-esr-102.9.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.21 · firefox-esr · FIXED · firefox-esr-102.9.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.22 · firefox-esr · FIXED · firefox-esr-102.9.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.23 · firefox-esr · FIXED · firefox-esr-102.9.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Copy sudo yum update --advisory=ALAS2-2023-1988
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. Quick answers How do I fix CVE-2023-28176? firefox: upgrade to 111.0; firefox esr: upgrade to 102.9; thunderbird: upgrade to 102.9. Exact commands for each OS are on this page.
Is CVE-2023-28176 being exploited? CVE-2023-28176 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-2023-28176 affect? CVE-2023-28176 affects firefox, firefox esr, thunderbird. Severity is high (CVSS 8.8). Memory safety bugs present in Firefox 110 and Firefox ESR 102.8. 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 vulnerabilit
How urgent is CVE-2023-28176? Priority 44/100. High severity
Software pages Mozilla Firefox vulnerabilities
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