This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1.
BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.
| Source | ID | Title |
|---|---|---|
Debian DSA |
DSA-6285-1 | bind9 security update |
Ubuntu USN |
USN-8293-1 | Bind vulnerabilities |
Solution
Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.23, 9.21.22, or 9.20.23-S1.
Workaround
No workarounds known.
Fri, 22 May 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-367 | |
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
Thu, 21 May 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* |
Wed, 20 May 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 20 May 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected. | |
| Title | SIG(0) validation during query flood may lead to undefined behavior | |
| First Time appeared |
Isc
Isc bind |
|
| Weaknesses | CWE-362 CWE-416 |
|
| CPEs | cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Isc
Isc bind |
|
| References |
| |
| Metrics |
cvssV3_1
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: isc
Published:
Updated: 2026-05-20T13:39:38.654Z
Reserved: 2026-04-09T06:40:58.672Z
Link: CVE-2026-5947
Updated: 2026-05-20T13:39:19.676Z
Status : Analyzed
Published: 2026-05-20T13:16:40.303
Modified: 2026-05-21T15:24:32.997
Link: CVE-2026-5947
OpenCVE Enrichment
Updated: 2026-05-22T02:30:16Z
Debian DSA
Ubuntu USN