Out-of-bounds Read Affecting unbound package, versions [,1.25.2)
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-UNMANAGED-UNBOUND-18306099
- published25 Jul 2026
- disclosed22 Jul 2026
- creditUnknown
Introduced: 22 Jul 2026
NewCVE-2026-56416 (opens in a new tab)How to fix?
Upgrade unbound to version 1.25.2 or higher.
Overview
Affected versions of this package are vulnerable to Out-of-bounds Read in the query_dname_tolower function when processing malformed DNSSEC records from a malicious authoritative server. An attacker can cause a denial of service or potentially disclose limited information by sending specially crafted DNSSEC records that trigger a heap buffer overflow. This is only exploitable if DNSSEC validation is enabled and may be more likely if msg-buffer-size is configured below its default value.
Workaround
This vulnerability can be mitigated by disabling DNSSEC validation in the configuration or restricting DNSSEC validation to trusted zones.