CVE-2025-40777
Fixed in a distro release EPSS 1%CVSS 7.5
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.
Products: ISC BIND 9
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine:v3.22 | bind | 9.20.11-r0 |
| Alpine:v3.23 | bind | 9.20.11-r0 |
| Alpine:v3.24 | bind | 9.20.11-r0 |
| Chainguard | bind | 0 |
| Chainguard | bind-dev | 0 |
| Chainguard | bind-dnssec-root | 0 |
| Chainguard | bind-dnssec-tools | 0 |
| Chainguard | bind-doc | 0 |
| Chainguard | bind-libs | 0 |
| Chainguard | bind-plugins | 0 |
| Chainguard | bind-tools | 0 |
| Debian:13 | bind9 | 1:9.20.11-1 |
| Debian:14 | bind9 | 1:9.20.11-1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | bind | 9.20.11-150700.3.6.1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP7 | bind | 9.20.11-150700.3.6.1 |
| Ubuntu:25.04 | bind9 | 1:9.20.4-3ubuntu1.2 |
| Wolfi | bind | 0 |
| Wolfi | bind-dev | 0 |
| Wolfi | bind-dnssec-root | 0 |
| Wolfi | bind-dnssec-tools | 0 |
| Wolfi | bind-doc | 0 |
| Wolfi | bind-libs | 0 |
| Wolfi | bind-plugins | 0 |
| Wolfi | bind-tools | 0 |
| openSUSE:Tumbleweed | bind | 9.20.11-1.1 |