CVE-2006-0061: xlockmore 5.13 and 5.22 segfaults when using libpam-opensc and returns the underlying xsession

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2006-0061 is a critical-severity flaw (CVSS 9.8) affecting xlockmore. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

xlockmore 5.13 and 5.22 segfaults when using libpam-opensc and returns the underlying xsession. This allows unauthorized users access to the X session.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.8% (top 21%)
CISA exploited list	No
Weakness	CWE-306
Published	2019-11-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: sillycycle

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

Am I affected?

Timeline

2019-11-06 02:15 UTCPublished CVE record published
2026-06-16 22:19 UTCUpdated Record last modified

sillycycle xlockmore DOWNGRADE

Affected: 5.13 · 5.22

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.13

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 5.13 (Debian / Ubuntu)

apt-cache madison xlockmore sudo apt install xlockmore=<VERSION_BEFORE_5.13> sudo apt-mark hold xlockmore

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

dnf --showduplicates list xlockmore sudo dnf downgrade xlockmore-<VERSION_BEFORE_5.13> sudo dnf versionlock add xlockmore

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-2006-0061?

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

Is CVE-2006-0061 being exploited?

CVE-2006-0061 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-2006-0061 affect?

CVE-2006-0061 affects xlockmore. Severity is critical (CVSS 9.8). xlockmore 5.13 and 5.22 segfaults when using libpam-opensc and returns the underlying xsession. This allows unauthorized users access to the X session.

How urgent is CVE-2006-0061?

Priority 64/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2012-4524 HIGH 7.5 UPGRADE MITIGATE xlockmore before 5.43 'dclock' security bypass vulnerability
CVE-2006-0062 CRITICAL 9.8 DOWNGRADE xlockmore 5.13 allows potential xlock bypass when FVWM switches to the same virtual desktop as a new Gaim wind

References

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