CVE-2026-77955

NVD: In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones (zonemd-check: yes) which are located below (but not at) a trust anchor allow for an attack window where (tampered with) zone contents are served (or stored to... NVD: This is caused by the needed DS/DNSKEY asynchronous resolution that needs to happen before the ZONEMD check completes. NVD: If a zonefile is written to disk (zonefile: option) while the ZONEMD check failed, the tampered data are reloaded on startup and available until ZONEMD verification concludes again.

Source-published summary

NVD: In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones (zonemd-check: yes) which are located below (but not at) a trust anchor allow for an attack window where (tampered with) zone contents are served (or stored to... NVD: This is caused by the needed DS/DNSKEY asynchronous resolution that needs to happen before the ZONEMD check completes. NVD: If a zonefile is written to disk (zonefile: option) while the ZONEMD check failed, the tampered data are reloaded on startup and available until ZONEMD verification concludes again.

Possible impact

This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for defensive exposure review.

Affected context

Affected product or version requires source confirmation.

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

This medium severity issue needs human triage to confirm exposure, affected versions, and vendor guidance for defensive exposure review.; CVSS 4.4 (MEDIUM); EPSS percentile 3; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

exposure unknown

Impact tags

Urgency reasons

Source-derived note

Summary derived from NVD description; unsafe procedural detail is not shown.

Redaction metadata

source summary used

True

fallback summary used

False

unsafe procedural detail present

false

raw source displayed

false

public summary redacted

true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.

Official references

• https://nvd.nist.gov/vuln/detail/CVE-2026-77955