CVE-2026-52686

Wildcard CNAME proof validation bypass

3.7 LowFix available

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: Low
Availability: None

Exploit likelihood

0.16%Down 0.1 points since Jul 23, 2026

What each source reports

CVE List Score used 3.7

Wildcard CNAME proof validation bypass

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.

Record: CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness: CWE-347
Updated: 2026-11-02

EUVDEUVD-2026-47931 3.7

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.

Record: EUVD-2026-47931
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-h7w8-vg64-36f2 3.7

The issue is a DNSSEC validation bypass where wildcard expansion proofs (NSEC/NSEC3 records) are...

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.

Record: GHSA-h7w8-vg64-36f2
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness: CWE-347
Updated: 2026-11-02

NVD 3.7

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.

Record: CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness: CWE-347
Updated: 2026-11-02

OSVALPINE-CVE-2026-52686 3.7

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.

Record: ALPINE-CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated: 2026-11-03

OSV 3.7

Wildcard CNAME proof validation bypass

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.

Record: CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-52686 3.7

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.

Record: DEBIAN-CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-52686 3.7

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.

Record: UBUNTU-CVE-2026-52686
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Updated: 2026-11-02

Affected products

powerdns recursor

Affected packages

Affected packages
Package	Affected	Fixed
`pdns-recursor` Alpine:v3.24	before 5.4.4-r0	5.4.4-r0
`pdns-recursor` Debian:12	All versions, plus listed versions 4.8.4-14.8.6-14.8.7-14.8.8-14.8.8-1+deb12u1 Show 45 moreShow less 4.9.0-14.9.0-24.9.1-14.9.1-24.9.1-34.9.1-44.9.2-14.9.2-24.9.3-14.9.4-14.9.5-15.0.5-15.0.7-15.0.7-25.0.9-15.1.3-15.1.3-25.2.0-15.2.0-25.2.0-35.2.0-45.2.0-55.2.1-15.2.2-15.2.2-25.2.4-15.2.4-25.2.5-15.3.0-15.3.0-25.3.0-35.3.0-45.3.0-55.3.1-15.3.3-15.3.4-15.3.4-25.3.5-15.4.0-15.4.1-15.4.1-25.4.2-15.4.2-25.4.3-15.4.4-1	None known
`pdns-recursor` Debian:13	before 5.2.12-0+deb13u1, plus listed versions 5.2.11-0+deb13u15.2.4-25.2.4-2+deb13u15.2.5-15.2.6-0+deb13u15.2.7-0+deb13u15.2.8-0+deb13u15.2.9-0+deb13u1	5.2.12-0+deb13u1
`pdns-recursor` Debian:14	before 5.4.4-1, plus listed versions 5.2.4-25.2.5-15.3.0-15.3.0-25.3.0-3 Show 13 moreShow less 5.3.0-45.3.0-55.3.1-15.3.3-15.3.4-15.3.4-25.3.5-15.4.0-15.4.1-15.4.1-25.4.2-15.4.2-25.4.3-1	5.4.4-1
`pdns-recursor` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 3.7.3-14.0.0~alpha1-14.0.0~alpha1-24.0.0~alpha2-24.0.0~alpha2-2ubuntu0.14.0.0~alpha2-2ubuntu0.1+esm1	None known
`pdns-recursor` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 4.0.6-14.0.6-1build14.0.7-14.1.1-14.1.1-1build14.1.1-24.1.1-2ubuntu0.1~esm1	None known
`pdns-recursor` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 4.2.0-64.2.1-14.2.1-1build14.2.1-1build24.2.1-1ubuntu0.1~esm1	None known
`pdns-recursor` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 4.4.2-34.6.0-1ubuntu14.6.0-1ubuntu1+esm1	None known
`pdns-recursor` Ubuntu:24.04:LTS	All versions, plus listed versions 4.9.0-24.9.1-44.9.2-14.9.2-1build14.9.2-24.9.3-14.9.3-1build24.9.3-1build3	None known
`pdns-recursor` Ubuntu:26.10	All versions, plus listed versions 5.3.5-15.4.3-15.4.5-1	None known
`pdns-recursor` Ubuntu:26.04:LTS	All versions, plus listed versions 5.2.4-2build25.3.1-15.3.3-15.3.4-15.3.4-1build15.3.4-25.3.5-1	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	affected, aliases, references	OSV
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-52686 is a low vulnerability (CVSS 3.7) in Powerdns Recursor, published July 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.16%, the 5th percentile. Fixed in pdns-recursor 5.4.4-r0.

References

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This page doesn't list everything

Left out here: 4 versions. The JSON record has them.