Cache poisoning possible with label count discrepancy, RRSIG, and wildcards (ISC BIND 9)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.40 % · percentile 34 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- isc
- NVD status
- Undergoing Analysis
Description
It is possible for an attacker's zone to respond to a query with an RRSIG that has a smaller number of labels than the zone in which the RRSIG is contained. This causes `named` to produce a wildcard name for a zone that is shorter than the attacker's zone, which can result in cache poisoning. For this attack to have any effect, the resolver under attack must have set `synth-from-dnssec yes;` (which is the default). This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
Weaknesses (CWE)
- CWE-1284 — Improper Validation of Specified Quantity in Input
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | isc |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | NVD · security-officer@isc.org (Secondary) |
European references
- ENISA EUVD · EUVD-2026-47709
- GCVE · GCVE-0-2026-11721
CERT-FR advisories
- CERTFR-2026-AVI-1376 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1256 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1206 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| ISC · BIND 9 | affected 9.11.0 ≤ 9.18.50 ; affected 9.20.0 ≤ 9.20.24 ; affected 9.21.0 ≤ 9.21.23 ; affected 9.11.3-S1 ≤ 9.18.50-S1 ; affected 9.20.9-S1 ≤ 9.20.24-S1 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |