CVE-2017-11125: libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_get_path function in util.c.

This month

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2017-11125 is a critical-severity flaw (CVSS 9.8) affecting xar. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_get_path function in util.c.

Why this priority

Critical severity
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	2.0% (top 20%)
CISA exploited list	No
Weakness	CWE-476
Published	2017-07-10
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: xar project

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

Am I affected?

Timeline

2017-07-10 03:29 UTCPublished CVE record published
2026-06-17 01:01 UTCUpdated Record last modified

xar project xar DOWNGRADE

Affected: 1.6.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.6.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.6.1 (Debian / Ubuntu)

apt-cache madison xar sudo apt install xar=<VERSION_BEFORE_1.6.1> sudo apt-mark hold xar

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

dnf --showduplicates list xar sudo dnf downgrade xar-<VERSION_BEFORE_1.6.1> sudo dnf versionlock add xar

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-2017-11125?

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

Is CVE-2017-11125 being exploited?

CVE-2017-11125 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-2017-11125 affect?

CVE-2017-11125 affects xar. Severity is critical (CVSS 9.8). libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_get_path function in util.c.

How urgent is CVE-2017-11125?

Priority 59/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2017-11124 CRITICAL 9.8 DOWNGRADE libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_unserialize function in archive.c.

References

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