Validating resolver can abort while caching a mismatched NOQNAME proof
If a BIND resolver sends a query for a DNSSEC-signed authoritative zone, and the authoritative server replies with a valid wildcard answer and signed NSEC3 proof, followed by an unsigned NSEC at the same owner name, it will trigger an unexpected program exit. 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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Sep 16, 2026
- Updated
- Sep 17, 2026
- EPSS
- 0.7% · 50th percentile
- CWE
- CWE-617
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Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · isc
- 7.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (isc). Independent of NVD's CPE analysis and usually ahead of it.
ISC BIND 9
- 9.11.0 and later · up to and including 9.18.50affected
- 9.20.0 and later · up to and including 9.20.27affected
- 9.21.0 and later · up to and including 9.21.25affected
- 9.11.3-S1 and later · up to and including 9.18.50-S1affected
- 9.20.9-S1 and later · up to and including 9.20.27-S1affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.22 | bind | before 9.20.29-r0 | 9.20.29-r0 |
| Debian:12 | bind9 | all versions | — |
| Debian:13 | bind9 | before 1:9.20.29-1~deb13u1 | 1:9.20.29-1~deb13u1 |
| Debian:14 | bind9 | before 1:9.20.29-1 | 1:9.20.29-1 |
| Red Hat:hummingbird:1 | bind | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-chroot | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-devel | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-dnssec-utils | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-doc | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-libs | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| Red Hat:hummingbird:1 | bind-utils | before 0:9.20.29-0.1.hum1 | 0:9.20.29-0.1.hum1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | bind | before 9.20.29-150700.3.32.2 | 9.20.29-150700.3.32.2 |
Same product
isc: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-12705DNS-over-HTTPS implementation suffers from multiple issues under heavy query load36Monitor
- CVE-2025-40775DNS message with invalid TSIG causes an assertion failure35Monitor
- CVE-2024-11187Many records in the additional section cause CPU exhaustion35Monitor
- CVE-2026-13321DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field34Monitor
- CVE-2025-40780Cache poisoning due to weak PRNG34Monitor
- CVE-2025-40778Cache poisoning attacks with unsolicited RRs34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| azl3 bind 9.20.26-1 on Azure Linux 3.0 | Release Notes | Microsoft (MSRC) |
| alpine:bind | 9.20.29-r0 · Alpine:v3.22 | Package registry (OSV) |
| debian:bind9 | 1:9.20.29-1~deb13u1 · Debian:13 | Package registry (OSV) |
| red hat:bind | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-chroot | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-devel | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-dnssec-utils | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-doc | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-libs | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:bind-utils | 0:9.20.29-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:bind | 9.20.29-150700.3.32.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-13878238 days apartMalformed BRID/HHIT records can cause named to terminate unexpectedly33Monitor
- CVE-2026-761630 days apartnamed aborts on a TKEY query when the user configuration has no global options statement30Monitor
- CVE-2026-1261756 days apartRecord ordering based unexpected exit with CNAME or DNAME30Monitor
- CVE-2026-1320456 days apartUnexpected exit in certain situations with NSEC and NSEC3 both present30Monitor
- CVE-2025-40777427 days apartA possible assertion failure when 'stale-answer-client-timeout' is set to '0'30Monitor
- CVE-2026-1082256 days apartKey Record using PRIVATEDNS algorithm may lead to unexpected exit26Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-617 · Reachable AssertionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- downloads.isc.org/isc/bind9/9.20.29
- downloads.isc.org/isc/bind9/9.21.26
- kb.isc.org/docs/cve-2026-80274
Vendor advisories and official records. Exploit/PoC links are deliberately left out.