crossbeam-channel Vulnerable to Double Free on Drop

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2025-4574: 0.56% estimated exploitation activity in the next 30 days; percentile 46.92 (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 internal Channel type's Drop method has a race which could, in some circumstances, lead to a double-free. This could result in memory corruption. Quoting from the upstream description in merge request \#1187: The problem lies in the fact that dicardallmessages contained two paths that could lead to head.block being read but only one of them would swap the value. This meant that dicardallmessages could end up observing a non-null block pointer (and therefore attempting to free it) without setting head.block to null. This would then lead to Channel::drop making a second attempt at dropping the same pointer. The bug was introduced while fixing a memory leak, in upstream MR \#1084, first published in 0.5.12. The fix is in upstream MR \#1187 and has been published in 0.5.15

Published by the source

10 Apr 2025, 14:30 UTC

Last modified by the source

25 Sep 2025, 21:13 UTC

Source last checked

26 Oct 2026, 15:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pg9f-39pc-qf8g

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# Patch Next advisory brief: CVE-2025-4574

Advisory: crossbeam-channel Vulnerable to Double Free on Drop
IDs: CVE-2025-4574, GHSA-pg9f-39pc-qf8g
Record: https://patchnext.com/advisories/cve-2025-4574 (revision 1, source checked 26 Oct 2026, 15:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: crossbeam-channel 0.5.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io crossbeam-channel: affected >= 0.5.12, < 0.5.15; fixed in 0.5.15

## Suggested inspection (read-only)
- crates.io crossbeam-channel: 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 crossbeam-channel.
- 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-pg9f-39pc-qf8g (GitHub-reviewed advisory GHSA-pg9f-39pc-qf8g lists affected ranges: crates.io crossbeam-channel >=0.5.12 <0.5.15)

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