CVE-2026-14986

Firmware memory corruption via unchecked I2C writes

Published Sep 14, 2026 · Updated Sep 14, 2026

Out-of-bounds write in Zephyr RTOS 4.2.0 through 4.4.1 allows physically proximate attackers to crash controllers via oversized I2C writes. In target_i2c_isr_fifo(), the driver appends host-supplied bytes to target_in_buffer before checking the cumulative w_index against the 256-byte buffer. The flaw requires I2C target buffer mode on an it51xxx device; a master on the same bus can corrupt adjacent firmware data, causing a crash or code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Zephyr RTOS 4.2.0 through 4.4.1 allows physically proximate attackers to crash controllers via oversized I2C writes. In target_i2c_isr_fifo(), the driver appends host-supplied bytes to target_in_buffer before checking the cumulative w_index against the 256-byte buffer. The flaw requires I2C target buffer mode on an it51xxx device; a master on the same bus can corrupt adjacent firmware data, causing a crash or code execution.

The record

CVE
CVE-2026-14986
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
Unavailable
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=4.2.0 <4.4.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=4.2.0 <4.4.2

Published CVSS scores

No CVSS assessment is available in this record.

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

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Your stack

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