What is CVE-2025-7403?

CVE-2025-7403 is a high-severity vulnerability in Zephyrproject Zephyr, classified under Write-what-where Condition. CVSS score: 7.6/10. Published 2025-09-19.

How severe is CVE-2025-7403?

High severity. CVSS v3 base score is 7.6 out of 10.

Is CVE-2025-7403 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Zephyrproject Zephyr

CVE-2025-7403

Unsafe handling in bt_conn_tx_processor causes a use-after-free, resulting in a write-before-zero. The written 4 bytes are attacker-controlled, enabling precise memory corruption.

Published 2025-09-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 9.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-123 — Write-what-where Condition

Public proof-of-concept exploits

rockmelodies/CVEInfo_

References

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9r46-cqqw-6j2j (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2025-7403?: CVE-2025-7403 is a high-severity vulnerability in Zephyrproject Zephyr, classified under Write-what-where Condition. CVSS score: 7.6/10. Published 2025-09-19.
How severe is CVE-2025-7403?: High severity. CVSS v3 base score is 7.6 out of 10.
Is CVE-2025-7403 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.