CVE-2013-4396: Use-after-free vulnerability in the doImageText function in dix/dixfonts.c in the xorg-server module before 1.

This month

MEDIUM 6.5DOWNGRADE

CVE-2013-4396 is a medium-severity flaw (CVSS 6.5) affecting x.org x11. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Use-after-free vulnerability in the doImageText function in dix/dixfonts.c in the xorg-server module before 1.14.4 in X.Org X11 allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code via a crafted ImageText request that triggers memory-allocation failure.

Why this priority

EPSS top 9%: very likely to be exploited

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

Risk facts

CVSS score	6.5 (Medium)
EPSS exploit chance	4.1% (top 9%)
CISA exploited list	No
Weakness	CWE-399
Published	2013-10-10
Last modified	2026-06-16

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

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

Am I affected?

Timeline

2013-10-10 10:55 UTCPublished CVE record published
2026-06-16 23:57 UTCUpdated Record last modified

x x.org x11 DOWNGRADE

Affected: 6.0 · 6.1 · 6.3 · 6.4 · 6.5.1 · 6.6 · 6.7 · 6.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

1. Check installed version

apt-cache policy x.org-x11 || rpm -q x.org-x11 || x.org-x11 --version

2. No fixed release: DOWNGRADE to a release before 6.0 (Debian / Ubuntu)

apt-cache madison x.org-x11 sudo apt install x.org-x11=<VERSION_BEFORE_6.0> sudo apt-mark hold x.org-x11

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

dnf --showduplicates list x.org-x11 sudo dnf downgrade x.org-x11-<VERSION_BEFORE_6.0> sudo dnf versionlock add x.org-x11

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.

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-2013-4396?

x.org x11: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2013-4396 being exploited?

CVE-2013-4396 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-2013-4396 affect?

CVE-2013-4396 affects x.org x11. Severity is medium (CVSS 6.5). Use-after-free vulnerability in the doImageText function in dix/dixfonts.c in the xorg-server module before 1.14.4 in X.Org X11 allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code

How urgent is CVE-2013-4396?

Priority 45/100. EPSS top 9%: very likely to be exploited

Related CVEs

CVE-2012-1699 LOW 3.6 DOWNGRADE UPGRADE The ProcSetEventMask function in difs/events.c in the xfs font server for X.Org X11R6 through X11R6.6 and XFre
CVE-2012-0064 MEDIUM 4.6 UPGRADE UPGRADE xkeyboard-config before 2.5 in X.Org before 7.6 enables certain XKB debugging functions by default, which allo

References

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