Cross-zone wildcard cache poisoning via RRSIG.labels manipulation
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| NLnet Labs | Unbound | unaffected |
|
| Package | CPE | Advisory | Released Date |
|---|---|---|---|
| Red Hat Hardened Images | |||
| unbound-main-1.25.2-0.1.hum1 | cpe:/a:redhat:hummingbird:1 | RHSA-2026:43588 | 2026-07-22T00:00:00Z |
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Nlnetlabs | Unbound |
|
Vendor Solution
This issue is fixed starting with version 1.25.2
| Source | ID | Title |
|---|---|---|
Debian DSA |
DSA-6507-1 | unbound security update |
Ubuntu USN |
USN-8946-1 | Unbound vulnerabilities |
Ubuntu USN |
USN-8946-2 | Unbound vulnerabilities |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.153% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat hummingbird |
|
| CPEs | cpe:/a:redhat:hummingbird:1 | |
| Vendors & Products |
Redhat
Redhat hummingbird |
|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Nlnetlabs
Nlnetlabs unbound |
|
| Vendors & Products |
Nlnetlabs
Nlnetlabs unbound |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone to poison arbitrary sibling zones under NSEC-signed parent domains. A malicious actor with one registered domain under an NSEC-signed TLD can serve malicious insecure DNS responses for unrelated sibling domains (sharing the same parent zone). Arbitrary delegations that do not exist under the parent domain and are covered by the parent's NSEC chain can be brought into insecure existence by fraudulent wildcard DS records (less labels than expected, unknown algorithm) from the malicious sibling domain. This allows the malicious actor to inject insecure wildcard records for those delegations. | |
| Title | Cross-zone wildcard cache poisoning via RRSIG.labels manipulation | |
| Weaknesses | CWE-345 | |
| References |
| |
| Metrics |
cvssV3_1
|