Improper Validation of Integrity Check Value Affecting unbound package, versions [1.16.2,1.25.2)
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.
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Test your applications- Snyk IDSNYK-UNMANAGED-UNBOUND-18507933
- published2 Aug 2026
- disclosed22 Jul 2026
- creditUnknown
Introduced: 22 Jul 2026
NewCVE-2026-42955 (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 Improper Validation of Integrity Check Value through the harden-referral-path process. An attacker can cause clients to receive outdated or misleading DNS responses by manipulating cached DNS records and extending the lifetime of stale information. This is only exploitable if the non-default harden-referral-path: yes configuration is enabled, as it removes the requirement for a client query.
Workaround
This vulnerability can be mitigated by ensuring harden-referral-path is set to no (the default), restricting recursive DNS access to trusted clients, and restarting the service to apply configuration changes.