Concurrency and locking defects in GSS-TSIG

published 2026-05-21 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-31260

cvss: 5.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits: 0; none known

Patch / fix

fixed in 1 distros 2

PowerDNS Authoritative 4.9.15, 5.0.5

debian alpine

pdns Debian 13 4.9.15-0+deb13u1
pdns Debian 14 5.0.5-1

debian advisories DEBIAN-CVE-2026-42002

pdns Alpine 3.24, Alpine 3.23 5.0.5-r0

alpine advisories ALPINE-CVE-2026-42002

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-2026-42002 updated 2026-06-28 cvss 5.9

pdns-recursor: pdns-recursor: Denial of service via GSS-TSIG concurrency and locking defects

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: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-21)

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
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 Authoritative

Classification

Weakness

CWE-364 Signal Handler Race Condition

References

docs.powerdns.com /authoritative/security-advisories/powerdns-advisory-powerdns-2026-06.html
broken-link

Sources

CVE List CVE-2026-42002
NVD CVE-2026-42002

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.

Summary