TI-2026-25673 Aliases CVE-2026-33256 GHSA-f4c2-g8rq-pq9h

Unbounded memory allocation by internal web server

MEDIUM 40CWE-770Published 2026-04-22 · Updated 2026-04-22

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-770.

Summary

An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00606 49th percentileScored 2026-11-07

Fix Fixed Recursor (PowerDNS): 5.4.1, 5.3.6, 5.2.9

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
PowerDNS	Recursor	5.4.0 to before 5.4.1; 5.3.0 to before 5.3.6; 5.2.0 to before 5.2.9	5.4.1, 5.3.6, 5.2.9	Patch available	CNA

Recursor VendorPowerDNS Affected 5.4.0 to before 5.4.1; 5.3.0 to before 5.3.6; 5.2.0 to before 5.2.9 Fixed in 5.4.1, 5.3.6, 5.2.9 Patch available CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:powerdns:recursor::::::::	5.2.0 to before 5.2.9; 5.3.0 to before 5.3.6	Vulnerable	PowerDNS
cpe:2.3:a:powerdns:recursor:5.4.0:::::::*	5.4.0	Vulnerable	PowerDNS

cpe:2.3:a:powerdns:recursor:*:*:*:*:*:*:*:* Versions 5.2.0 to before 5.2.9; 5.3.0 to before 5.3.6 Vulnerable ·PowerDNS
cpe:2.3:a:powerdns:recursor:5.4.0:*:*:*:*:*:*:* Versions 5.4.0 Vulnerable ·PowerDNS

Remediation

Fix · CNA Recursor (PowerDNS) Fixed in 5.4.1, 5.3.6, 5.2.9

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-04-22
PowerDNS Recursor 5.2.9, 5.3.6, 5.4.1
9 records Highest priority Priority MEDIUM 2 MEDIUM, 7 LOW
Other records, highest priority first
- TI-2026-25675 Crafted zones can cause increased resource usagePriority MEDIUM 40
- TI-2026-25677 Insufficient input validation of internal webserverPriority LOW 39
- TI-2026-25674 Insufficient input validation of internal webserverPriority LOW 39
Show all 9 records →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2026-33256
2026-10-03 Alias added: GHSA-f4c2-g8rq-pq9h
2026-10-25 EPSS moved to the below the 50th percentile

References

Advisory 1

https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-03.html

TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
TI-2023-27773 The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance… CVSS 3.1HIGH 7.5
TI-2015-01678 The label decompression functionality in PowerDNS Recursor 3.5.x, 3.6.x before 3.6.3, and… CVSS 2.0HIGH 7.8
TI-2018-12065 Out-of-bounds read in [UNKNOWN] pdns-recursor CVSS 3.0HIGH 7.5
TI-2017-11091 NULL pointer dereference in PowerDNS pdns-recursor CVSS 3.0HIGH 7.5
TI-2014-07065 PowerDNS Recursor before 3.6.2 does not limit delegation chaining, which allows remote… CVSS 2.0MEDIUM 5.0

See all 49 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences