CVE-2026-52686 Wildcard CNAME proof validation bypass
Low 3.7
Published
Updated
Check this codebase for CVE-2026-52686 and fix it if it is affected.
What it is: CVE-2026-52686 is a low-severity vulnerability in PowerDNS Recursor, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-52686 in the wild and no public exploit code.
Affected product: PowerDNS Recursor. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-52686/ (Markdown: https://insights.sbomify.com/CVE-2026-52686/index.md)
Attackers can bypass DNSSEC validation for wildcard CNAME/DNAME records, allowing spoofed DNS responses to be accepted as valid.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52686?
CVE-2026-52686 is a low-severity vulnerability in PowerDNS Recursor, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The issue is a DNSSEC validation bypass where wildcard expansion proofs (NSEC/NSEC3 records) are accepted without signature validation when the wildcard answer is a CNAME or DNAME record.
Weakness: CWE-347
Which versions are affected by CVE-2026-52686?
How do I fix CVE-2026-52686?
Apply the vendor's patch.
Is CVE-2026-52686 being exploited?
There is no known exploitation of CVE-2026-52686 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-52686, GHSA-h7w8-vg64-36f2, UBUNTU-CVE-2026-52686.