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CVE-2025-40775

CVE-2025-40775 · DNS message with invalid TSIG causes an assertion failure

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.5 · High · EPSS 15.3% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • bind 9

    Versions
    • ≥ 9.20.0, ≤ 9.20.8: Affected (custom)
    • ≥ 9.21.0, ≤ 9.21.7: Affected (custom)

    No fix published

  • bind9 Debian:13

    Affected ranges
    • ECOSYSTEM: < 1:9.20.9-1

    Update to 1:9.20.9-1

  • bind9 Debian:14

    Affected ranges
    • ECOSYSTEM: < 1:9.20.9-1

    Update to 1:9.20.9-1

Original sources

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