CVE-2012-4512: The CSS parser (khtml/css/cssparser.cpp) in Konqueror in KDE 4.7.3 allows remote attackers to cause a denial o

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HIGH 8.8WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2012-4512 is a high-severity flaw (CVSS 8.8) affecting kde, enterprise linux, enterprise linux desktop. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The CSS parser (khtml/css/cssparser.cpp) in Konqueror in KDE 4.7.3 allows remote attackers to cause a denial of service (crash) and possibly read memory via a crafted font face source, related to "type confusion."

Why this priority

High severity
EPSS top 4%: very likely to be exploited
Public exploit reference
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	11.7% (top 4%)
CISA exploited list	No
Weakness	CWE-843
Published	2020-02-08
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: kde · redhat

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-02-08 19:15 UTCPublished CVE record published
2026-06-16 23:45 UTCUpdated Record last modified

kde kde DOWNGRADE

Affected: 4.7.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.7.3

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.7.3 (Debian / Ubuntu)

apt-cache madison kde sudo apt install kde=<VERSION_BEFORE_4.7.3> sudo apt-mark hold kde

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

dnf --showduplicates list kde sudo dnf downgrade kde-<VERSION_BEFORE_4.7.3> sudo dnf versionlock add kde

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.

redhat enterprise linux MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

redhat enterprise linux desktop MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

redhat enterprise linux server eus MITIGATE

Affected: 6.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.3

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.

redhat enterprise linux workstation MITIGATE

Affected: 6.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Konqueror 4.7.3 - Memory Corruption

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-2012-4512?

kde: downgrade or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation; enterprise linux desktop: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2012-4512 being exploited?

CVE-2012-4512 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-2012-4512 affect?

CVE-2012-4512 affects kde, enterprise linux, enterprise linux desktop. Severity is high (CVSS 8.8). The CSS parser (khtml/css/cssparser.cpp) in Konqueror in KDE 4.7.3 allows remote attackers to cause a denial of service (crash) and possibly read memory via a crafted font face source, related to "type confusion."

How urgent is CVE-2012-4512?

Priority 65/100. High severity; EPSS top 4%: very likely to be exploited; Public exploit reference; On your watchlist

Related CVEs

CVE-2012-4515 MEDIUM 6.8 MITIGATE Use-after-free vulnerability in khtml/rendering/render_replaced.cpp in Konqueror in KDE 4.7.3, when the contex
CVE-2012-4514 MEDIUM 5.0 UPGRADE rendering/render_replaced.cpp in Konqueror in KDE before 4.9.3 allows remote attackers to cause a denial of se
CVE-2012-4513 MEDIUM 6.4 MITIGATE khtml/imload/scaledimageplane.h in Konqueror in KDE 4.7.3 allows remote attackers to cause a denial of service
CVE-2008-1671 MEDIUM 4.6 MITIGATE start_kdeinit in KDE 3.5.5 through 3.5.9, when installed setuid root, allows local users to cause a denial of
CVE-2008-1670 HIGH 9.3 MITIGATE Heap-based buffer overflow in the progressive PNG Image loader (decoders/pngloader.cpp) in KHTML in KDE 4.0.x

References

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