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Fencer Vulns
medium 5.3

CVE-2026-33594 json

Outgoing DoH excessive memory allocation

published 2026-04-22 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-24931

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.

Patch / fix

  • PowerDNS DNSdist 1.9.13, 2.0.4
  • dnsdist Debian 13 1.9.14-0+deb13u1
  • dnsdist Debian 14 2.0.4-1

debian advisories DEBIAN-CVE-2026-33594

  • dnsdist SLES for SAP applications 16.0, SLES 16.0 1.9.13-160000.1.1

suse advisories SUSE-SU-2026:22319-1

  • dnsdist openSUSE Leap 16.0 1.9.13-160000.1.1
  • dnsdist openSUSE Tumbleweed 2.0.5-1.1

opensuse advisories openSUSE-SU-2026:21015-1openSUSE-SU-2026:10632-1

  • dnsdist Alpine 3.24, Alpine 3.23 2.0.4-r0

alpine advisories ALPINE-CVE-2026-33594

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-33594 updated cvss 7.5

dnsdist: outgoing DoH excessive memory allocation

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • PowerDNS DNSdist

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.