---
id: "CVE-2026-115567"
kind: "vulnerability"
aliases: ["CVE-2026-115567", "GHSA-5wjr-9356-4wc8"]
title: "Tokio: Race condition in `tokio::time::Interval`"
severity: "medium"
cvss: 5.8
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "tokio", "fixed": ["1.54.1"], "affected": "= 1.54.0", "ecosystem": "cargo"}]
ecosystems: ["cargo"]
tags: ["cargo", "cwe-362", "package", "rust", "tokio"]
not_affected_if: ["not-on-1.54.0", "sleep-or-timeout-only"]
published_at: "2026-10-23T18:17:21+00:00"
first_seen_at: "2026-10-23T20:59:05+00:00"
updated_at: "2026-10-23T21:57:34+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-5wjr-9356-4wc8", "first_seen_at": "2026-10-23T20:59:05+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115567", "first_seen_at": "2026-10-23T21:57:34+00:00"}]
---

# Tokio: Race condition in `tokio::time::Interval`

Tokio's tokio::time::Interval has a race condition with the runtime time driver on the multi-threaded runtime, which can drop a timer entry and cause a use-after-free in safe Rust. An attacker gets crashes or heap memory corruption in applications that use Interval, and the advisory does not describe a code execution path.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- cargo:tokio affected = 1.54.0 fixed 1.54.1

## How to check

Run cargo tree -i tokio and check whether the resolved version is 1.54.0 in Cargo.lock.
Search the codebase for tokio::time::Interval, .tick().await, or interval( calls on the multi-threaded runtime.

## Fix

Upgrade tokio to 1.54.1 or later, which fixes this issue.

## Timeline

- 2026-10-23T20:59:05+00:00 ghsa https://github.com/advisories/GHSA-5wjr-9356-4wc8
- 2026-10-23T21:57:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115567

## From the sources

### Summary

On the multi-threaded runtime, there is a race condition between `Interval::poll_tick` and the runtime's time driver.

This affects `Interval` only. `Sleep` and `Timeout` are **not** affected.

### Details

In Tokio v1.54.0, a race condition between `tokio::time::Interval::poll_tick` (including `.tick().await`) and the runtime time driver can drop an internal timer entry without synchronizing with the driver thread that is firing it. This causes a data race and use-after-free on the timer's waker and task state in safe Rust, leading to assertion panics, task reference-count corruption, or heap memory corruption.

This bug was introduced by https://github.com/tokio-rs/tokio/pull/8458, and it was fixed by https://github.com/tokio-rs/tokio/pull/8692.

### Impact

This may lead to crashes and use-after-frees in applications using `Interval` on a multi-threaded runtime.

Since this issue is known to lead to crashes in production systems, the v1.54.0 release of Tokio has been yanked.

### Credits

Thank you to [creepycode](https://github.com/ByteZ1337) and [carabistouille](https://github.com/carabistouflette) for reporting this privately using the procedure outlined in our security policy. They both reported the issue independently of each other.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_