CVE-2026-10642

Hang via CTS-blocked TX busy-loop

Published Jun 24, 2026 · Updated Jun 24, 2026

Infinite loop in the PL011 UART driver in Zephyr RTOS 4.1.0 through 4.4.1 allows physically proximate attackers to hang the executing context. The pl011_irq_tx_enable() loop keeps invoking the application callback while TXIM remains set, but a full FIFO makes pl011_fifo_fill() return zero without clearing that bit. CTS hardware flow control must be enabled, and a wired UART peer must withhold CTS during transmission; the result is an availability-only hang.

CVSS severity6.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Infinite loop in the PL011 UART driver in Zephyr RTOS 4.1.0 through 4.4.1 allows physically proximate attackers to hang the executing context. The pl011_irq_tx_enable() loop keeps invoking the application callback while TXIM remains set, but a full FIFO makes pl011_fifo_fill() return zero without clearing that bit. CTS hardware flow control must be enabled, and a wired UART peer must withhold CTS during transmission; the result is an availability-only hang.

The record

CVE
CVE-2026-10642
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-835, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.1.0 <4.5.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=4.1.0 <4.5.0

Published CVSS scores

6.5GitHub Security AdvisoryCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.6Zephyr Project CNACVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo