CVE-2026-66484

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 34/100
Published: 2026-08-10 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: Active
S: X
AT: None
VC: None
VI: Low
VA: None

Description

GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files. This issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad

Weakness Classification (1)

Bug Bounty Relevance

34 / 100
✓ No authentication
✓ Low complexity

CVSS Score

4.6 / 10.0 v4.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.20%
Raw Score 0.001970
Percentile 9.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00197
2026-10-28
0.00197

Intelligence Sources

nvd ref →