CVE-2026-19662 — qpcache NOQNAME proof use-after-free crashes recursive resolver

An attacker may be able to cause a `named` resolver to abort. The attack requires inducing the victim resolver to send multiple queries for a DNSSEC-signed zone hosted by an authoritative server under the control of the attacker. If the auth responds with a particular sequence of crafted answers, and those answers arrive in a particular order with particular timing, the `named` resolver will encounter a use-after-free bug, and abort. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

Published Sep 16, 2026Updated Sep 17, 2026Sources: cvelistV5, isc

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

chance of exploitation in 30 days

Affects

isc

bind_9

CVSS base

5.9

MEDIUM

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

isc

Products (1)

bind 9

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.9	CVSS 3.1	MEDIUM	—	—	cvelistV5

Weakness & attack patterns

CWE-416

References

2 on the record

kb.isc.org/docs/cve-2026-19662
vendor-advisory
downloads.isc.org/isc/bind9/9.20.29
patch

Elsewhere on this site

iscevery CVE for this vendor
CWE-416other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.