CVE-2025-4574 is a medium-severity (CVSS 6.5) CWE-415 vulnerability in crossbeam-channel. A fix is available for crossbeam-channel — see the affected versions and patch details below.
Crossbeam-channel: crossbeam-channel vulnerable to double free on drop
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-4574.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
crossbeam-channelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
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
dicard_all_messagescontained two paths that could lead tohead.blockbeing read but only one of them would swap the value. This meant thatdicard_all_messagescould end up observing a non-null block pointer (and therefore attempting to free it) without settinghead.blockto null. This would then lead toChannel::dropmaking 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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | crossbeam-channel | ≥ 0.5.12&&< 0.5.15 | 0.5.15cargo update -p crossbeam-channel --precise 0.5.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crossbeam-channel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update crossbeam-channel to 0.5.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-4574 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2025-4574 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2025-4574 in your dependencies?
Find it across crates.io, including transitive dependencies.