7.5

CVE-2026-81634

Medienbericht

Possible heap buffer overflow during DNSSEC canonicalization

In NLnet Labs Unbound up to and including 1.26.0, a 255 length query name with a large TCP response can lead to a heap buffer overflow during the RRSet canonicalisation routine. This is caused by missing to add the first owner name into the buffer length check. A malicious actor operating a malicious name server or tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can trigger the vulnerability.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Nlnetlabs ≫ Unbound Version < 1.26.1
VulnDex Vulnerability Enrichment
Diese Information steht angemeldeten Benutzern zur Verfügung. Login Login
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.36% 0.291
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
sep@nlnetlabs.nl 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-122 Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Für Zugriff zu Vulnerability Intelligence ist ein VulnDex Zugang erforderlich.
VulnDex Intel
Media Report
17.09.2026 15:48
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81634.txt
Patch
Vendor Advisory