CVE-2020-7666: This affects all versions of package github.com/u-root/u-root/pkg/cpio

This week

HIGH 7.5REMOTEMITIGATE

CVE-2020-7666 is a high-severity flaw (CVSS 7.5) affecting u-root. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

This affects all versions of package github.com/u-root/u-root/pkg/cpio. It is vulnerable to leading, non-leading relative path traversal attacks and symlink based (relative and absolute) path traversal attacks in cpio file extraction.

Why this priority

High 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	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.5% (top 25%)
CISA exploited list	No
Weakness	CWE-22
Published	2020-09-01
Last modified	2026-06-17

Publisher (CNA): Snyk · Vendor: u-root

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

Am I affected?

Timeline

2020-09-01 14:15 UTCPublished CVE record published
2026-06-17 03:25 UTCUpdated Record last modified

u-root u-root MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy u-root || rpm -q u-root || u-root --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2020-7666?

u-root: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-7666 being exploited?

CVE-2020-7666 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-2020-7666 affect?

CVE-2020-7666 affects u-root. Severity is high (CVSS 7.5). This affects all versions of package github.com/u-root/u-root/pkg/cpio. It is vulnerable to leading, non-leading relative path traversal attacks and symlink based (relative and absolute) path traversal attacks in cpio file extraction.

How urgent is CVE-2020-7666?

Priority 55/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

GitHub vulnerabilities

Related CVEs

CVE-2020-7669 HIGH 7.5 MITIGATE This affects all versions of package github.com/u-root/u-root/pkg/tarutil
CVE-2020-7665 HIGH 7.5 MITIGATE This affects all versions of package github.com/u-root/u-root/pkg/uzip

References

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