GHSA-pg9f-39pc-qf8g
crossbeam-channel Vulnerable to Double Free on Drop
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
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 | 0.5.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crossbeam-channel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update crossbeam-channel to 0.5.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pg9f-39pc-qf8g is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-pg9f-39pc-qf8g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pg9f-39pc-qf8g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pg9f-39pc-qf8g in your dependencies?
O3 detects GHSA-pg9f-39pc-qf8g across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.