| Name | CVE-2026-3591 |
| Description | A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| bind9 (PTS) | bullseye | 1:9.16.50-1~deb11u2 | fixed |
| bullseye (security) | 1:9.16.50-1~deb11u4 | fixed | |
| bookworm | 1:9.18.41-1~deb12u1 | fixed | |
| bookworm (security) | 1:9.18.47-1~deb12u1 | fixed | |
| trixie | 1:9.20.18-1~deb13u1 | vulnerable | |
| trixie (security) | 1:9.20.21-1~deb13u1 | fixed | |
| forky, sid | 1:9.20.22-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| bind9 | source | bullseye | (not affected) | |||
| bind9 | source | bookworm | (not affected) | |||
| bind9 | source | trixie | 1:9.20.21-1~deb13u1 | |||
| bind9 | source | (unstable) | 1:9.20.21-1 |
[bookworm] - bind9 <not-affected> (Vulnerable code not present)
[bullseye] - bind9 <not-affected> (Vulnerable code not present)
https://kb.isc.org/docs/cve-2026-3591
https://gitlab.isc.org/isc-projects/bind9/-/commit/e85af603df437eddbe472d874742918688ec8f75 (v9.20.21)
https://gitlab.isc.org/isc-projects/bind9/-/commit/4a2048ea7f98b7ad9528463a045abc9d224a0f43 (v9.20.21)