CVE-2026-52688: powerdns recursor Improper Certificate Validation
CVSS: 7.5v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-52688DEBIAN-CVE-2026-52688
Published 23-07-2026Last modified 23-07-2026
Vulnerability summary
CVE-2026-52688 is a high (CVSS 7.5) Improper Certificate Validation vulnerability in powerdns recursor. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.7% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.18%
0%100%
Low · +0.05 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 23-07-2026PublishedVulnerability first disclosed.
- 23-07-2026Last modifiedVulnerability information updated.
Description
RRSIGs with too few labels can lead to bypass of DNSSEC wildcard validation
CVSS metrics
4 scores · 4 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
+0.05 pp
From 0.12% on 20-09-2026
20-09-202620-10-2026
EPSS score0.18%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- pdns-recursorAll versions (No fix recorded) | < 5.2.12-0+deb13u1 | < 5.4.4-1
Powerdns1 product
- recursor≥ 5.2.0, < 5.2.12 | ≥ 5.3.0, < 5.3.9 | ≥ 5.4.0, < 5.4.4
Ubuntu1 product
- pdns-recursorAll versions (No fix recorded)
3 vendors · 3 products
