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Response snapshot Oct 27, 2026, 03:07 UTC

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VulnerabilityCVE-2026-115567

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

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.

At a glance

Exploited
Not known
Severity
5.8 Medium (CVSS 4.0)
Chance of exploitation
0.1% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: tokio: 1.54.1. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-5wjr-9356-4wc8 (opens a new tab)

What happened

### 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

Continue reading

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.

Affected package ranges reported by GitHub: tokio: = 1.54.0

Scores and how they were measured

CVSS base severity

5.8

Version 4.0As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.1%

Scored Percentile 1.3%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-5wjr-9356-4wc8 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-5wjr-9356-4wc8, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-115567, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 23). Tokio: Race condition in `tokio::time::Interval` (CVE-2026-115567). https://kevwire.com/record/CVE-2026-115567

MLA

"Tokio: Race condition in `tokio::time::Interval` (CVE-2026-115567)." KEVWire, 23 Oct. 2026, kevwire.com/record/CVE-2026-115567.

Chicago

KEVWire. "Tokio: Race condition in `tokio::time::Interval` (CVE-2026-115567)." Last modified October 23, 2026. https://kevwire.com/record/CVE-2026-115567.

Evidence summary (plain text)

Tokio: Race condition in `tokio::time::Interval` (Oct 23, 2026).
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.
CVSS 5.8 (version 4.0; evidence as of Oct 23, 2026; https://github.com/advisories/GHSA-5wjr-9356-4wc8).
EPSS 0.1% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-115567&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-5wjr-9356-4wc8: https://github.com/advisories/GHSA-5wjr-9356-4wc8
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-115567&date=2026-10-26
Record ID: CVE-2026-115567.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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