SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-3330

RCE/DOS: Linked-list corruption leading to large out-of-bounds write while sorting for forged fragment list in Zephyr.

HIGH 8.8EPSS 0.61%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

RCE/DOS: Linked-list corruption leading to large out-of-bounds write while sorting for forged fragment list in Zephyr. Zephyr versions >= >=2.4.0 contain Out-of-bounds Write (CWE-787). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fj4r-373f-9456

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.61% probability · 49th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
zephyrproject/zephyr
Source
vulnerabilities@zephyrproject.org
EPSS trend
0%3%5%26 October 2026: 0.61%26 October 202626 October 2026

EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.