CVE-2026-5947
EUVD-2026-3111020.05.2026, 13:16
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.
Affected Products (NVD)
| Vendor | Product | Version |
|---|---|---|
| isc | bind | 9.20.0 ≤ 𝑥 < 9.20.23 |
| isc | bind | 9.21.0 ≤ 𝑥 < 9.21.22 |
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
| Vendor | Product | Version | Source |
|---|---|---|---|
| Red Hat | Red Hat Hardened Images | 9.18.48-1.1.hum1 ≤ 𝑥 < * | ADP |
Debian Releases
Ubuntu Releases
Ubuntu Product | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| bind9-libs |
| ||||||||||||||||
| bind9 |
| ||||||||||||||||
| isc-dhcp |
|
openSUSE / SLES Releases
Common Weakness Enumeration
- CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race ConditionThe software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state.
References