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Fencer Vulns
high 7.5

CVE-2019-16866 json

Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query.

published 2019-10-03 7 y ago modified 2026-10-08 31 d ago also EUVD-2019-7375

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.5%
EPSS 3.5% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule.

Patch / fix

  • nlnetlabs unbound 1.9.4
  • unbound Debian 14, Debian 13, Debian 12 1.9.4-1

debian advisories DEBIAN-CVE-2019-16866

  • unbound openSUSE Tumbleweed 1.13.2-1.2

opensuse advisories openSUSE-SU-2024:11005-1

  • unbound Alpine 3.10 1.9.1-r3
  • unbound Alpine 3.24, Alpine 3.23, Alpine 3.22 +11 more 1.9.4-r0
  • unbound Alpine 3.8 1.7.3-r1
  • unbound Alpine 3.9 1.8.3-r2

alpine advisories ALPINE-CVE-2019-16866

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

  • unbound Arch Linux 1.9.4-1

arch linux advisories AVG-1042

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-2019-16866 updated cvss 5.3

unbound: uninitialized memory accesses leads to crash via a crafted NOTIFY query

  • Red Hat Enterprise Linux 8 unbound, unbound-libs, python3-unbound
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 unbound, unbound-libs, unbound-python Red Hat Enterprise Linux 7 unbound, unbound-libs, unbound-python
    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
31 d ago

Exploit prediction

3.51% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions
  • CWE-908 Use of Uninitialized Resource

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.