CVE•Published 2026-05-18•Modified 2026-07-23•0 articles on news•5 live references•NVD data

CVE-2026-42009Gnu · Gnutls

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

Exploit Prediction Scoring System · top 32% of all CVEs

Weaknesses (CWE)

CWE-475Undefined Behavior for Input to API

Description

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.

Timeline

Published 2026-05-18

Modified 2026-07-23

External references

NVD MITRE Exploit-DB GitHub PoC VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-42009

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Gnu Gnutls"

All exposed Gnu Gnutls instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Gnutls"

HTTP body or banner mentions "Gnutls" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-42009