SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-38821

A heap-based buffer overflow vulnerability exists in openNDS before 11.0.0 that allows an unauthenticated attacker on the captive portal network to crash the openNDS daemon (denial of service) and potentially achieve remote code execution.

HIGH 7.1EPSS 0.20%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A heap-based buffer overflow vulnerability exists in openNDS before 11.0.0 that allows an unauthenticated attacker on the captive portal network to crash the openNDS daemon (denial of service) and potentially achieve remote code execution. This is in http_microhttpd.c.

CVSS 3.1
7.1 HIGHCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS
0.20% probability · 10th percentile
CISA KEV
Not listed
Weakness
CWE-122
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.