CVE-2026-3591

medium

Published 2026-03-25 · Modified 2026-05-21

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

5.4

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

5.4

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.

Predictions

Exploit likelihood

64%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

OS	Version	Status	Fixed in
debian	bookworm	fixed	`0`
debian	bullseye	fixed	`0`
debian	forky	fixed	`1:9.20.21-1`
debian	sid	fixed	`1:9.20.21-1`
debian	trixie	fixed	`1:9.20.21-1~deb13u1`
sles		affected

Application impact

Vendor	Product	Versions	Fixed
isc	bind	`{"startIncluding":"9.20.0","endExcluding":"9.20.21"}`	`9.20.21`

References

CWEs

CWE-305 CWE-562

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.