CVE-2026-55828
Received Received - Intake

Path Traversal in qbee transport

Publication date: 2026-09-15

Last updated on: 2026-09-15

Assigner: GitHub, Inc.

Description
qbee transport is a remote access transport protocol implementation. Prior to 1.26.25, the extractTar routine uses strictly lexical path validation that does not account for on-disk symlinks created earlier in the extraction process. A crafted tar archive can use a symlink chain to write or overwrite files one directory level above the intended extraction path. When qbee-agent performs the extraction with root privileges, this permits a root-privileged file write outside the intended destination. This issue is fixed in version 1.26.25.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-15
Last Modified
2026-09-15
Generated
2026-09-15
AI Q&A
2026-09-15
EPSS Evaluated
N/A
NVD
CVE-2026-55828
EUVD
EUVD-2026-78783

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
qbee-io transport 1.26.25
qbee-io transport to 1.26.27 (exc)
qbee qbee_transport to 1.26.25 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CWE-59 The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability affects qbee transport, a remote access transport protocol implementation. It involves a flaw in the extractTar routine where lexical path validation fails to consider on-disk symlinks created during extraction. A malicious tar archive can exploit this by using a symlink chain to write or overwrite files outside the intended extraction path. When qbee-agent runs with root privileges, this allows writing files as root outside the target directory.

Detection Guidance

This vulnerability involves a crafted tar archive exploiting symlink chains during extraction. To detect it, inspect tar archives for suspicious symlinks or paths using commands like 'tar -tvf archive.tar' to list contents. Check for files outside intended directories or unexpected symlink targets.

Impact Analysis

If exploited, this vulnerability could allow an attacker to overwrite critical system files or create malicious files with root privileges. This could lead to system compromise, unauthorized access, or disruption of services. Systems using qbee transport versions prior to 1.26.25 are at risk.

Mitigation Strategies

Upgrade qbee-agent to version 1.26.25 or later to patch the vulnerability. If upgrading is not immediately possible, avoid using qbee-agent with untrusted tar archives or restrict its privileges. Monitor for unusual file writes or symlink activity in extraction directories.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-55828. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart