CVE-2025-40775

DiscoveredMay 21, 2025UpdatedApr 15, 2026

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.

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CVSS v3.1

7.5 HIGH

EPSS

15.3%

probability of exploitation in 30 days

CISA KEV

Not listed

no confirmed exploitation reported

News coverage

sources referencing this CVE

Related IOCs

seen in the same coverage

EPSS Trend

Aug 16, 2026 → Oct 29, 2026

▲ 2.82pp

12.5% → 15.3% over 4 tracked changes

CVSS v3.1 Detail

Attack VectorNETWORK

Attack ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

ScopeUNCHANGED

ConfidentialityNONE

IntegrityNONE

AvailabilityHIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Connections

1 relationships

CWE-232

source

Timeline

disclosure → media coverage

May 21, 2025

Disclosure — published as a CVE record. · last revised by NVD Apr 15, 2026

Public PoC (1)

github.com/AlexSvobo/nhi-zero-trust-bypass

Unverified third-party code — review before executing.