Amazon Linux 2027 Preview Security Advisory: ALAS2027-2026-009
Advisory Released Date: 2026-09-18
Advisory Updated Date: 2026-11-02
Severity:
Critical
Issue Overview:
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. (CVE-2026-81642)
Affected Packages:
unbound
Issue Correction:
Run dnf update unbound --releasever 2027.0.20260914 or dnf update --advisory ALAS2027-2026-009 --releasever 2027.0.20260914 to update your system.
New Packages:
aarch64:
unbound-debuginfo-1.25.2-3.amzn2027.aarch64
python3-unbound-1.25.2-3.amzn2027.aarch64
python3-unbound-debuginfo-1.25.2-3.amzn2027.aarch64
unbound-utils-debuginfo-1.25.2-3.amzn2027.aarch64
unbound-utils-1.25.2-3.amzn2027.aarch64
unbound-libs-debuginfo-1.25.2-3.amzn2027.aarch64
unbound-dracut-1.25.2-3.amzn2027.aarch64
unbound-debugsource-1.25.2-3.amzn2027.aarch64
unbound-anchor-debuginfo-1.25.2-3.amzn2027.aarch64
unbound-devel-1.25.2-3.amzn2027.aarch64
unbound-anchor-1.25.2-3.amzn2027.aarch64
unbound-1.25.2-3.amzn2027.aarch64
unbound-libs-1.25.2-3.amzn2027.aarch64
src:
unbound-1.25.2-3.amzn2027.src
x86_64:
unbound-debuginfo-1.25.2-3.amzn2027.x86_64
unbound-dracut-1.25.2-3.amzn2027.x86_64
unbound-devel-1.25.2-3.amzn2027.x86_64
unbound-debugsource-1.25.2-3.amzn2027.x86_64
python3-unbound-debuginfo-1.25.2-3.amzn2027.x86_64
unbound-libs-debuginfo-1.25.2-3.amzn2027.x86_64
unbound-anchor-debuginfo-1.25.2-3.amzn2027.x86_64
unbound-utils-debuginfo-1.25.2-3.amzn2027.x86_64
unbound-anchor-1.25.2-3.amzn2027.x86_64
unbound-utils-1.25.2-3.amzn2027.x86_64
python3-unbound-1.25.2-3.amzn2027.x86_64
unbound-1.25.2-3.amzn2027.x86_64
unbound-libs-1.25.2-3.amzn2027.x86_64