CVE-2023-39928: A use-after-free vulnerability exists in the MediaRecorder API of Webkit WebKitGTK 2.40.5

This month

HIGH 8.8WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2023-39928 is a high-severity flaw (CVSS 8.8) affecting webkitgtk, debian linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use-after-free vulnerability exists in the MediaRecorder API of Webkit WebKitGTK 2.40.5. A specially crafted web page can abuse this vulnerability to cause memory corruption and potentially arbitrary code execution. A user would need to to visit a malicious webpage to trigger this vulnerability.

Why this priority

High severity
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.4% (top 27%)
CISA exploited list	No
Weakness	CWE-416
Published	2023-10-06
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: debian · fedoraproject · webkitgtk

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-10-06 16:15 UTCPublished CVE record published
2026-06-17 06:12 UTCUpdated Record last modified

webkitgtk webkitgtk DOWNGRADE

Affected: 2.40.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.40.5

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.40.5 (Debian / Ubuntu)

apt-cache madison webkitgtk sudo apt install webkitgtk=<VERSION_BEFORE_2.40.5> sudo apt-mark hold webkitgtk

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list webkitgtk sudo dnf downgrade webkitgtk-<VERSION_BEFORE_2.40.5> sudo dnf versionlock add webkitgtk

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.

debian debian linux MITIGATE

Affected: 11.0 · 12.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

fedoraproject fedora MITIGATE

Affected: 37

Fixed in: no fixed release known

Safe to downgrade to: a release before 37

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2023-39928?

webkitgtk: downgrade or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-39928 being exploited?

CVE-2023-39928 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-2023-39928 affect?

CVE-2023-39928 affects webkitgtk, debian linux, fedora. Severity is high (CVSS 8.8). A use-after-free vulnerability exists in the MediaRecorder API of Webkit WebKitGTK 2.40.5. A specially crafted web page can abuse this vulnerability to cause memory corruption and potentially arbitrary code execution. A user would need to t

How urgent is CVE-2023-39928?

Priority 54/100. High severity; On your watchlist

Software pages

Debian vulnerabilities · WebKit vulnerabilities · Apple Safari and WebKit vulnerabilities

Related CVEs

CVE-2023-42843 MEDIUM 4.3 UPGRADE UPGRADE An inconsistent user interface issue was addressed with improved state management
CVE-2023-40397 CRITICAL 9.8 UPGRADE UPGRADE The issue was addressed with improved checks
CVE-2023-32370 MEDIUM 5.3 UPGRADE UPGRADE A logic issue was addressed with improved validation
CVE-2023-28198 HIGH 8.8 UPGRADE UPGRADE A use-after-free issue was addressed with improved memory management

References

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