Cargo crates in third party registries can override the cached source of other crates

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-5223: 0.29% estimated exploitation activity in the next 30 days; percentile 22.16 (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.

The Rust Security Response Team was notified that Cargo incorrectly handled symlinks inside of crate tarballs downloaded from third-party registries, allowing a malicious crate to override the source code of another crate from the same registry. This vulnerability is tracked as CVE-2026-5223. The severity of the vulnerability is medium for users of third-party registries. Users of crates.io are not affected, as crates.io forbids uploading crates containing any symlink. Overview When building a crate, Cargo extracts its source code in a local cache (stored within ~/.cargo), reusing it for any future build. Cargo includes protections to prevent any file from being extracted outside of the crate's own cache directory. It was discovered that it's possible to craft a malicious tarball able to extract files one level below the crate's own cache directory. With the way the cache is structured, that allowed the malicious crate to override the cache of other crates belonging to the same…

Published by the source

26 Jun 2026, 21:48 UTC

Last modified by the source

26 Jun 2026, 21:48 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-jq42-7mfv-hm57

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# Patch Next advisory brief: CVE-2026-5223

Advisory: Cargo crates in third party registries can override the cached source of other crates
IDs: CVE-2026-5223, GHSA-jq42-7mfv-hm57
Record: https://patchnext.com/advisories/cve-2026-5223 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: cargo 0.97.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io cargo: affected < 0.97.0; fixed in 0.97.0

## Suggested inspection (read-only)
- crates.io cargo: 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 cargo.
- 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-jq42-7mfv-hm57 (GitHub-reviewed advisory GHSA-jq42-7mfv-hm57 lists affected ranges: crates.io cargo >=0 <0.97.0)

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