CVE-2026-35501 Affecting unbound-anchor package, versions <0:1.17.1-1.amzn2023.0.17
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-AMZN2023-UNBOUNDANCHOR-21705306
- published25 Oct 2026
- disclosed21 Oct 2026
Introduced: 21 Oct 2026
NewCVE-2026-35501 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 unbound-anchor to version 0:1.17.1-1.amzn2023.0.17 or higher.
This issue was patched in ALAS2023-2026-3313.
NVD Description
Note: Versions mentioned in the description apply only to the upstream unbound-anchor package and not the unbound-anchor package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
When NLnet Labs Unbound 1.0.1 up to and including version 1.26.1 is configured with both a root trust anchor and an additional 'trust-anchor:' for an island-of-security zone whose parent is provably insecure under the root chain, a malicious actor with a forged NSEC reply with the SOA bit cleared can trick Unbound to treat the configured trust island as insecure. This happens because the DNSSEC validator in Unbound accepts and caches the NSEC insecure response bypassing the RRSIG validation that the validator was supposed to do. The acceptance of the NSEC record at the trust anchor apex was allowed due to and old fix for type DS and NSEC queries from clients when trust anchor for that name existed.