Vulnerability · Published Aug 28, 2026 · Assigned by mitre
CVE-2026-38821
High 7.1
In plain English
A high-severity heap buffer overflow in openNDS from openNDS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).
Severity (CVSS 3.1)7.1High
Exploit odds (30 days)0.3%top 76.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | opennds | no fix listed | DEBIAN-CVE-2026-38821 |
| Debian:13 | opennds | no fix listed | DEBIAN-CVE-2026-38821 |
| Ubuntu:26.04:LTS | opennds | no fix listed | UBUNTU-CVE-2026-38821 |
| Ubuntu:26.10 | opennds | no fix listed | UBUNTU-CVE-2026-38821 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L