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CVE-2025-7403VulnerabilityPublished Updated

CVE-2025-7403: zephyrproject-rtos Zephyr · Write-what-where Condition

Affects zephyrproject-rtos ZephyrSource CVE Database V5

0

Not known to be exploited · CVSS 7.6 High : upgrade to 4.2.0 soon.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score
7.6High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 4.2.0
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Sep 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Upgrade zephyrproject-rtos Zephyr to 4.2.0.

Affected software

ProductAffectedFixed in
zephyrproject-rtosZephyrAffected
  • <4.2.0
Fixed in
  • 4.2.0
GitHubZephyrpkg:github/ZephyrOther threatsAffected
  • <4.2.0
Fixed in
  • 4.2.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

CVE-2025-7403 is a high-severity vulnerability in Zephyr RTOS versions prior to 4.2.0. It involves unsafe handling in the bt_conn_tx_processor component, causing a use-after-free condition that leads to a write-before-zero. This flaw allows an attacker to control 4 bytes of memory written, enabling precise memory corruption.

References

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