CVE-2025-40775

High

Description

When an incoming DNS protocol message includes a Transaction Signature (TSIG), BIND always checks it. If the TSIG contains an invalid value in the algorithm field, BIND immediately aborts with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.8 and 9.21.0 through 9.21.7.

SeverityHigh

CVSS7.5

Exploit probability—

ProductBIND 9

PublishedMay 21, 2025

First seenMay 21, 2025

Weakness typeCWE-232CWE-232

How to fix

Vendor advisories

kb.isc.org/docs/cve-2025-40775

Affected products

Product	Affected versions	Fixed in
ISC BIND 9	9.20.0 ≤ v ≤ 9.20.8, 9.21.0 ≤ v ≤ 9.21.7	—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.