CVE-2025-11713: Insufficient escaping in the “Copy as cURL” feature could have been used to trick a user into executing unexpe

Routine

HIGH 8.1UPGRADEUPGRADE

CVE-2025-11713 is a high-severity flaw (CVSS 8.1) affecting firefox, thunderbird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Insufficient escaping in the “Copy as cURL” feature could have been used to trick a user into executing unexpected code on Windows. This did not affect the application when running on other operating systems. This vulnerability was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-116
Published	2025-10-14
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

2025-10-14 13:15 UTCPublished CVE record published
2026-10-23 23:10 UTCUpdated Record last modified

mozilla firefox UPGRADE

Affected: < 140.4.0 · < 144.0

Fixed in: 140.4.0, 144.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 140.4.0 (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 thunderbird UPGRADE

Affected: < 140.4.0 · >= 141.0 and < 144.0

Fixed in: 140.4.0, 144.0

Safe to downgrade to: a release before 141.0

1. Check installed version

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

2. UPGRADE to 140.4.0 (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.

3. If no update is available yet, DOWNGRADE to a release before 141.0 (Debian / Ubuntu)

apt-cache madison thunderbird sudo apt install thunderbird=<VERSION_BEFORE_141.0> sudo apt-mark hold thunderbird

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list thunderbird sudo dnf downgrade thunderbird-<VERSION_BEFORE_141.0> sudo dnf versionlock add thunderbird

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · sugar-calculator · FIXED · 47-14.fc46 · FEDORA-2026-38eeb9e279 · source

sudo dnf upgrade --advisory=FEDORA-2026-38eeb9e279

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Ubuntu 22.04 · firefox · NOT AFFECTED

Ubuntu 24.04 · firefox · NOT AFFECTED

Ubuntu 25.04 · firefox · NOT AFFECTED

Ubuntu 25.10 · firefox · NOT AFFECTED

Ubuntu 24.04 · thunderbird · NOT AFFECTED

Debian 12 · firefox-esr · NOT AFFECTED

Debian 13 · firefox-esr · NOT AFFECTED

Debian 12 · thunderbird · NOT AFFECTED

Debian 13 · thunderbird · NOT AFFECTED

RHEL 10 · firefox · NOT AFFECTED

RHEL 10 · rhel10/firefox-flatpak · NOT AFFECTED

RHEL 10 · rhel10/thunderbird-flatpak · NOT AFFECTED

RHEL 10 · thunderbird · NOT AFFECTED

RHEL 6 · firefox · NOT AFFECTED

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-2025-11713?

firefox: upgrade to 140.4.0, 144.0; thunderbird: upgrade to 140.4.0, 144.0. Exact commands for each OS are on this page.

Is CVE-2025-11713 being exploited?

CVE-2025-11713 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-2025-11713 affect?

CVE-2025-11713 affects firefox, thunderbird. Severity is high (CVSS 8.1). Insufficient escaping in the “Copy as cURL” feature could have been used to trick a user into executing unexpected code on Windows. This did not affect the application when running on other operating systems. This vulnerability was fixed in

How urgent is CVE-2025-11713?

Priority 33/100. High severity

Software pages

Windows vulnerabilities · Mozilla Firefox vulnerabilities · curl vulnerabilities

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References

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