CVE-2025-7403: zephyrproject-rtos Zephyr · Write-what-where Condition
Affects zephyrproject-rtos ZephyrSource CVE Database V5
Not known to be exploited · CVSS 7.6 High : upgrade to 4.2.0 soon.
Data as of 26 Oct 2026, 06:26 UTC
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| zephyrproject-rtosZephyr | Affected
| Fixed in
|
GitHubZephyrpkg:github/ZephyrOther threats | Affected
| Fixed in
|
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.