CVE-2023-25742: When importing a SPKI RSA public key as ECDSA P-256, the key would be handled incorrectly causing the tab to c MEDIUM 6.5 UPGRADE UPGRADE UPGRADE
CVE-2023-25742 is a medium-severity flaw (CVSS 6.5) affecting firefox, firefox esr, thunderbird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
When importing a SPKI RSA public key as ECDSA P-256, the key would be handled incorrectly causing the tab to crash. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
Why this priority No elevated risk signals yet A fixed release or distro patch exists.
Risk facts CVSS score 6.5 (Medium) Attack vector Network (remote) Attack complexity Low Privileges needed None User interaction Required EPSS exploit chance 0.6% (top 50%) CISA exploited list No 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: < 110.0
Fixed in: 110.0
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 110.0 (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: < 102.8
Fixed in: 102.8
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 102.8 (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: < 102.8
Fixed in: 102.8
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 102.8 (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 ELN · selinux-policy ·
FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 ·
source Copy sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2
Fedora 46 · sugar-toolkit-gtk3 ·
FIXED · 0.122-2.fc46 · FEDORA-2026-d11eb2faf0 ·
source Copy sudo dnf upgrade --advisory=FEDORA-2026-d11eb2faf0
Ubuntu 20.04 · firefox · FIXED · 110.0+build3-0ubuntu0.20.04.1
Copy sudo apt update && sudo apt install --only-upgrade firefox
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox)" ge "110.0+build3-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 22.04 · firefox · NOT AFFECTED
Ubuntu 24.04 · firefox · NOT AFFECTED
Ubuntu 22.04 · thunderbird · FIXED · 1:102.8.0+build2-0ubuntu0.22.04.1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.8.0+build2-0ubuntu0.22.04.1" && echo PATCHED || echo STILL-VULNERABLE
Ubuntu 20.04 · thunderbird · FIXED · 1:102.8.0+build2-0ubuntu0.20.04.1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.8.0+build2-0ubuntu0.20.04.1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · firefox-esr · FIXED · 102.8.0esr-1
Copy sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.8.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · firefox-esr · FIXED · 102.8.0esr-1
Copy sudo apt update && sudo apt install --only-upgrade firefox-esr
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' firefox-esr)" ge "102.8.0esr-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 12 · thunderbird · FIXED · 1:102.8.0-1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.8.0-1" && echo PATCHED || echo STILL-VULNERABLE
Debian 13 · thunderbird · FIXED · 1:102.8.0-1
Copy sudo apt update && sudo apt install --only-upgrade thunderbird
dpkg --compare-versions "$(dpkg-query -W -f='${Version}' thunderbird)" ge "1:102.8.0-1" && echo PATCHED || echo STILL-VULNERABLE
RHEL 7 · firefox · FIXED · firefox-102.8.0-2.el7_9
Copy sudo dnf upgrade --advisory=RHSA-2023:0812
rpm -q firefox
RHEL 7 · thunderbird · FIXED · thunderbird-102.8.0-2.el7_9
Copy sudo dnf upgrade --advisory=RHSA-2023:0817
rpm -q thunderbird
RHEL 8 · firefox · FIXED · firefox-102.8.0-2.el8_7
Copy sudo dnf upgrade --advisory=RHSA-2023:0808
rpm -q firefox
RHEL 8 · thunderbird · FIXED · thunderbird-102.8.0-2.el8_7
Copy sudo dnf upgrade --advisory=RHSA-2023:0821
rpm -q thunderbird
RHEL 8.1 Update Services for SAP Solutions · firefox · FIXED · firefox-102.8.0-2.el8_1
Copy sudo dnf upgrade --advisory=RHSA-2023:0806
rpm -q firefox
Alpine 3.20 · firefox-esr · FIXED · firefox-esr-102.8.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.21 · firefox-esr · FIXED · firefox-esr-102.8.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.22 · firefox-esr · FIXED · firefox-esr-102.8.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Alpine 3.23 · firefox-esr · FIXED · firefox-esr-102.8.0-r0
Copy apk add --upgrade firefox-esr
apk info -v firefox-esr
Copy sudo yum update --advisory=ALAS2-2023-1983
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-2023-25742? firefox: upgrade to 110.0; firefox esr: upgrade to 102.8; thunderbird: upgrade to 102.8. Exact commands for each OS are on this page.
Is CVE-2023-25742 being exploited? CVE-2023-25742 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-2023-25742 affect? CVE-2023-25742 affects firefox, firefox esr, thunderbird. Severity is medium (CVSS 6.5). When importing a SPKI RSA public key as ECDSA P-256, the key would be handled incorrectly causing the tab to crash. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.
How urgent is CVE-2023-25742? Priority 35/100. No elevated risk signals yet.
Software pages Mozilla Firefox vulnerabilities
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