High severity · published Oct 21, 2026
CVE-2026-94300
Concurrent GSS-TSIG messages corrupt memory
8.1
CVSS
1%
EPSS
No
On KEV
Description
Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 61% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
B9
BIND 9 · ISC
9.11.0 through 9.18.50; 9.20.0 through 9.20.29; 9.21.0 through 9.21.26; 9.11.3-S1 through 9.18.50-S1; 9.20.9-S1 through 9.20.29-S1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-94300
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-94300
downloads.isc.org
https://downloads.isc.org/isc/bind9/9.20.30
downloads.isc.org
https://downloads.isc.org/isc/bind9/9.21.27
kb.isc.org
https://kb.isc.org/docs/cve-2026-94300
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