CVE-2026-19033Unauthenticated IXFR deltas are applied to the live zone before TSIG verification
Updated under an hour ago ()
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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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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.
- CVSS
- 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
- Weakness (CWE)
- CWE-349
- 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
- Awaiting Analysis
- Record last updated
- Sep 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
ISC BIND 9 isc:bind_9 (from the name) | from 9.11.0 through 9.18.50; from 9.20.0 through 9.20.27; from 9.21.0 through 9.21.25; from 9.11.3-S1 through 9.18.50-S1; from 9.20.9-S1 through 9.20.27-S1 | CNA record |
References
- https://kb.isc.org/docs/cve-2026-19033vendor-advisory
- https://downloads.isc.org/isc/bind9/9.20.29patch
- https://downloads.isc.org/isc/bind9/9.21.26patch
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.