CVE-2025-40777
A possible assertion failure when 'stale-answer-client-timeout' is set to '0'
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A possible assertion failure when 'stale-answer-client-timeout' is set to '0'
If a `named` caching resolver is configured with `serve-stale-enable` `yes`, and with `stale-answer-client-timeout` set to `0` (the only allowable value other than `disabled`), and if the resolver, in the process of resolving a query, encounters a CNAME chain involving a specific combination of cached or authoritative records, the daemon will abort with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.10, 9.21.0 through 9.21.9, and 9.20.9-S1 through 9.20.10-S1.
Reserved 2025-04-16 | Published 2025-07-16 | Updated 2025-07-16 | Assigner isckb.isc.org/docs/cve-2025-40777 (CVE-2025-40777)
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