High 8.6Published Oct 22, 2025

CVE-2025-40780Cache poisoning due to weak PRNG

Updated under an hour ago (Oct 26, 2026, 9:23 PM ET)

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It affects ISC BIND 9. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for ISC BIND 9

Exploited in the last 30 days

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: 8.6 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Weakness (CWE): CWE-341
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: isc
NVD analysis: Deferred
Record last updated: Nov 4, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

ISC BIND 9 isc:bind_9 (from the name)	from 9.16.0 through 9.16.50; from 9.18.0 through 9.18.39; from 9.20.0 through 9.20.13; from 9.21.0 through 9.21.12; from 9.16.8-S1 through 9.16.50-S1; from 9.18.11-S1 through 9.18.39-S1; from 9.20.9-S1 through 9.20.13-S1	CNA record

References

References

https://kb.isc.org/docs/cve-2025-40780	vendor-advisory
http://www.openwall.com/lists/oss-security/2025/10/22/1

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.