Heap-based Buffer Overflow Affecting python2-unbound package, versions <0:1.7.3-15.amzn2.0.16


Severity

Recommended
0.0
critical
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.96% (61st percentile)

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  • Snyk IDSNYK-AMZN2-PYTHON2UNBOUND-19895837
  • published18 Sept 2026
  • disclosed16 Sept 2026

Introduced: 16 Sep 2026

CVE-2026-81642  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 python2-unbound to version 0:1.7.3-15.amzn2.0.16 or higher.
This issue was patched in ALAS2-2026-3928.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python2-unbound package and not the python2-unbound package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound.

CVSS Base Scores

version 3.1