uutils coreutils: cp/install/mv/ln --suffix alone does not enable backup mode (silent data loss vs GNU)

Exploitation

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

CVSS 4.0

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

determinebackupmode in src/uucore/src/lib/features/backupcontrol.rs only checks --backup/-b and returns BackupMode::None when only --suffix is given. GNU enables backup mode when --suffix is used alone (defaulting to existing/numbered, or $VERSIONCONTROL). Affects cp, install, mv, ln which share this code. Impact: users/scripts relying on --suffix to back up a file before overwrite get silent data loss; breaks GNU compatibility across four utilities. Recommendation: enable backup mode when --suffix is present. Note: this is primarily a GNU-compatibility/data-safety divergence rather than a classic exploitable vulnerability — review whether it warrants a CVE. Remediation: Acknowledged by Canonical; fixed in PR #9741 (uucore: use --suffix to enable backup mode), commit 939ab037a, merged 2025-12-21. determinebackupmode now has a --suffix-alone branch that resolves the mode from $VERSIONCONTROL (defaulting to existing). Released in uucore 0.6.0 and later (vulnerable: < 0.6.0). Regression…

Published by the source

7 Jul 2026, 19:36 UTC

Last modified by the source

7 Jul 2026, 19:36 UTC

Source last checked

26 Oct 2026, 15:43 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fqf6-gxhh-2xhw

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# Patch Next advisory brief: GHSA-fqf6-gxhh-2xhw

Advisory: uutils coreutils: cp/install/mv/ln --suffix alone does not enable backup mode (silent data loss vs GNU)
IDs: GHSA-fqf6-gxhh-2xhw
Record: https://patchnext.com/advisories/ghsa-fqf6-gxhh-2xhw (revision 1, source checked 26 Oct 2026, 15:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: uucore 0.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io uucore: affected < 0.6.0; fixed in 0.6.0

## Suggested inspection (read-only)
- crates.io uucore: 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 uucore.
- 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-fqf6-gxhh-2xhw (GitHub-reviewed advisory GHSA-fqf6-gxhh-2xhw lists affected ranges: crates.io uucore >=0 <0.6.0)

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