CVE-2023-3600: During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potenti

Q: How do I fix CVE-2023-3600?

firefox: upgrade to 115.0.2; firefox esr: upgrade to 115.0.2; thunderbird: upgrade to 115.0.1. Exact commands for each OS are on this page.

Q: Is CVE-2023-3600 being exploited?

CVE-2023-3600 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-3600 affect?

CVE-2023-3600 affects firefox, firefox esr, thunderbird. Severity is high (CVSS 8.8). During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potentially exploitable crash. This vulnerability affects Firefox < 115.0.2, Firefox ESR < 115.0.2, and Thunderbird < 115.0.1.

This month

HIGH 8.8UPGRADEUPGRADEUPGRADE

CVE-2023-3600 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.

During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potentially exploitable crash. This vulnerability affects Firefox < 115.0.2, Firefox ESR < 115.0.2, and Thunderbird < 115.0.1.

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	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-416
Published	2023-07-12
Last modified	2026-10-23

Publisher (CNA): Mozilla Corporation · Vendor: mozilla

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-07-12 14:15 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

mozilla firefox UPGRADE

Affected: < 115.0.2

Fixed in: 115.0.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy firefox || rpm -q firefox || firefox --version

2. UPGRADE to 115.0.2 (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: < 115.0.2

Fixed in: 115.0.2

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 115.0.2 (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: < 115.0.1

Fixed in: 115.0.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy thunderbird || rpm -q thunderbird || thunderbird --version

2. UPGRADE to 115.0.1 (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 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

Ubuntu 20.04 · firefox · FIXED · 115.0.2+build1-0ubuntu0.20.04.1

sudo apt update && sudo apt install --only-upgrade firefox dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "115.0.2+build1-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · firefox · NOT AFFECTED

Ubuntu 24.04 · firefox · NOT AFFECTED

Ubuntu 20.04 · thunderbird · FIXED · 1:115.3.1+build1-0ubuntu0.20.04.1

sudo apt update && sudo apt install --only-upgrade thunderbird dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:115.3.1+build1-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · thunderbird · FIXED · 1:115.3.1+build1-0ubuntu0.22.04.2

sudo apt update && sudo apt install --only-upgrade thunderbird dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:115.3.1+build1-0ubuntu0.22.04.2" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · thunderbird · NOT AFFECTED

Debian 13 · thunderbird · NOT AFFECTED

RHEL 7 · thunderbird · FIXED · thunderbird-115.3.1-1.el7_9

sudo dnf upgrade --advisory=RHSA-2023:5475 rpm -q thunderbird

RHEL 7 · firefox · FIXED · firefox-115.3.1-1.el7_9

sudo dnf upgrade --advisory=RHSA-2023:5477 rpm -q firefox

RHEL 8 · thunderbird · FIXED · thunderbird-115.3.1-1.el8_8

sudo dnf upgrade --advisory=RHSA-2023:5428 rpm -q thunderbird

RHEL 8 · firefox · FIXED · firefox-115.3.1-1.el8_8

sudo dnf upgrade --advisory=RHSA-2023:5433 rpm -q firefox

RHEL 8.1 Update Services for SAP Solutions · thunderbird · FIXED · thunderbird-115.3.1-1.el8_1

sudo dnf upgrade --advisory=RHSA-2023:5438 rpm -q thunderbird

Alpine 3.20 · firefox-esr · FIXED · firefox-esr-115.0.2-r0

apk add --upgrade firefox-esr apk info -v firefox-esr

Alpine 3.21 · firefox-esr · FIXED · firefox-esr-115.0.2-r0

apk add --upgrade firefox-esr apk info -v firefox-esr

Alpine 3.22 · firefox-esr · FIXED · firefox-esr-115.0.2-r0

apk add --upgrade firefox-esr apk info -v firefox-esr

Alpine 3.23 · firefox-esr · FIXED · firefox-esr-115.0.2-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.

Quick answers

How do I fix CVE-2023-3600?

firefox: upgrade to 115.0.2; firefox esr: upgrade to 115.0.2; thunderbird: upgrade to 115.0.1. Exact commands for each OS are on this page.

Is CVE-2023-3600 being exploited?

CVE-2023-3600 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-2023-3600 affect?

CVE-2023-3600 affects firefox, firefox esr, thunderbird. Severity is high (CVSS 8.8). During the worker lifecycle, a use-after-free condition could have occurred, which could have led to a potentially exploitable crash. This vulnerability affects Firefox < 115.0.2, Firefox ESR < 115.0.2, and Thunderbird < 115.0.1.

How urgent is CVE-2023-3600?

Priority 43/100. High severity

Software pages

Mozilla Firefox vulnerabilities · Mozilla Thunderbird vulnerabilities

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References

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