Threats Tagged 'cve-2026-40622'

Multiple security vulnerabilities have been identified in the unbound DNS resolver packages used in Red Hat Enterprise Linux 8. These include denial of service issues caused by excessive EDNS options, large DNS resource record sets, and degraded resolution performance, as well as a cache manipulation vulnerability via a 'ghost domain names' attack. Red Hat has issued an important security advisory with updates addressing these issues.

Multiple security vulnerabilities have been identified in the unbound DNS resolver packages used in Red Hat Enterprise Linux 9. These include denial of service issues caused by excessive EDNS options, large DNS resource record sets, and degraded resolution performance, as well as a cache manipulation vulnerability via 'ghost domain names'. Red Hat has released security updates addressing these issues.

Multiple security vulnerabilities affecting the unbound DNS resolver in Red Hat Enterprise Linux 10 have been addressed. These include denial of service issues caused by excessive EDNS options, large DNS resource record sets, and degraded resolution performance, as well as a cache manipulation vulnerability via 'ghost domain names'. The vulnerabilities have been rated with a security impact of Important by Red Hat Product Security. Updates are available to remediate these issues in Red Hat Enterprise Linux 10 and related CodeReady Linux Builder products across multiple architectures.

This update includes the following RPMs: unbound: * python3-unbound-1.25.1-1.hum1 (aarch64, x86_64) * unbound-1.25.1-1.hum1 (aarch64, x86_64) * unbound-anchor-1.25.1-1.hum1 (aarch64, x86_64) * unbound-devel-1.25.1-1.hum1 (aarch64, x86_64) * unbound-dracut-1.25.1-1.hum1 (aarch64, x86_64) * unbound-libs-1.25.1-1.hum1 (aarch64, x86_64) * unbound-munin-1.25.1-1.hum1 (noarch) * unbound-utils-1.25.1-1.hum1 (aarch64, x86_64) * unbound-1.25.1-1.hum1.src (src)

NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost) zone and be able to query a vulnerable Unbound. A single client NS query can cause Unbound to overwrite the cached expired parent-side referral NS rrset with the child-side apex NS rrset and essentially extend the ghost domain window by up to one cached TTL configured value ('cache-max-ttl'). In configurations where 'harden-referral-path: yes' is used (non-default configuration), no client NS query is required since Unbound implicitly performs that query. Unbound 1.25.1 contains a patch with a fix that does not allow extension of TTLs for (parent) NS records regardless of their trust.