go.qbee.io/transport: Symlink-chain path traversal in tar extraction (one level outside destination)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.0 · CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-55828: 0.38% estimated exploitation activity in the next 30 days; percentile 31.50 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The go.qbee.io/transport library is affected by a symlink-chain path traversal vulnerability in its extractTar routine. The library's path validation is strictly lexical and fails to account for on-disk symlinks created earlier in the extraction process. Consequently, a crafted tar archive can be used to write or overwrite files one directory level above the intended extraction path. In the case of qbee-agent, which runs with root privileges, this vulnerability permits a root-privileged file write outside the intended destination. Patches The issue has been addressed in version v1.26.25

Published by the source

19 Jun 2026, 21:15 UTC

Last modified by the source

26 Aug 2026, 10:59 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-f9m7-vc86-p6jj

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# Patch Next advisory brief: CVE-2026-55828

Advisory: go.qbee.io/transport: Symlink-chain path traversal in tar extraction (one level outside destination)
IDs: CVE-2026-55828, GHSA-f9m7-vc86-p6jj
Record: https://patchnext.com/advisories/cve-2026-55828 (revision 1, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: go.qbee.io/transport 1.26.25. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go go.qbee.io/transport: affected < 1.26.25; fixed in 1.26.25

## Suggested inspection (read-only)
- Go go.qbee.io/transport: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on go.qbee.io/transport.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-f9m7-vc86-p6jj (GitHub-reviewed advisory GHSA-f9m7-vc86-p6jj lists affected ranges: Go go.qbee.io/transport >=0 <1.26.25)

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