Heap-based Buffer Overflow Affecting unbound-debuginfo package, versions <0:1.17.1-1.amzn2023.0.15


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.48% (39th percentile)

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  • Snyk IDSNYK-AMZN2023-UNBOUNDDEBUGINFO-20246583
  • published29 Sept 2026
  • disclosed16 Sept 2026

Introduced: 16 Sep 2026

CVE-2026-81634  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 unbound-debuginfo to version 0:1.17.1-1.amzn2023.0.15 or higher.
This issue was patched in ALAS2023-2026-3127.

NVD Description

Note: Versions mentioned in the description apply only to the upstream unbound-debuginfo package and not the unbound-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1