Missing Release of Resource after Effective Lifetime Affecting unbound package, versions [1.20.0,1.25.2)
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-18507936
- published2 Aug 2026
- disclosed22 Jul 2026
- creditUnknown
Introduced: 22 Jul 2026
NewCVE-2026-56444 (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 Missing Release of Resource after Effective Lifetime via incorrect accounting in the serve-expired process. An attacker can cause the exhaustion of the reply address counter by sending specially crafted queries, resulting in the server dropping new legitimate client queries and degrading resolution services. This is only exploitable if both serve-expired and discard-timeout are enabled with non-default values.
Workaround
This vulnerability can be mitigated by configuring serve-expired-client-timeout to not exceed discard-timeout when serve-expired: yes is enabled, or by disabling the serve-expired feature if not required.