High severity · published Oct 22, 2025
CVE-2025-40780
Cache poisoning due to weak PRNG
8.6
CVSS
0.5%
EPSS
No
On KEV
Description
In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use.
This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
B9
BIND 9 · ISC
9.16.0 through 9.16.50; 9.18.0 through 9.18.39; 9.20.0 through 9.20.13; 9.21.0 through 9.21.12; 9.16.8-S1 through 9.16.50-S1; 9.18.11-S1 through 9.18.39-S1; +1 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-40780
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-40780
kb.isc.org
https://kb.isc.org/docs/cve-2025-40780
www.openwall.com
http://www.openwall.com/lists/oss-security/2025/10/22/1
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