CVE-2026-19033

Summary

For a secondary zone with transfers restricted by TSIG, named may start to serve the data provided in a zone transfer before the final message with the TSIG signature arrives. This could allow an attacker that does not actually possess a valid TSIG signature to send unauthorized zone contents to a secondary server. Although no TSIG signature ever arrives, named does not rollback to the pre-transfer state. To exploit the vulnerability, the transfer must be a multi-message TCP IXFR, as described by RFC 8945. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

Affected Software

VendorProductVersion RangeStatus
ISCBIND 99.11.0 <= 9.18.50affected
ISCBIND 99.20.0 <= 9.20.27affected
ISCBIND 99.21.0 <= 9.21.25affected
ISCBIND 99.11.3-S1 <= 9.18.50-S1affected
ISCBIND 99.20.9-S1 <= 9.20.27-S1affected

Weaknesses

  • CWE-349: CWE-349 Acceptance of Extraneous Untrusted Data With Trusted Data

Workarounds

No workarounds known.

References