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Fencer Vulns
high 8.1

CVE-2026-12246 json

Out of bounds stack write with crafted APL RR

published 2026-06-25 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-39184

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes.

Patch / fix

  • NLnet Labs NSD 4.14.3
  • nsd Debian 14 4.14.3-1

debian advisories DEBIAN-CVE-2026-12246

  • nsd Ubuntu Pro 16.04 LTS 4.1.7-1ubuntu0.1~esm1
  • nsd Ubuntu Pro 18.04 LTS 4.1.17-1ubuntu0.1~esm1
  • nsd Ubuntu Pro 20.04 LTS 4.1.26-1ubuntu0.1~esm1
  • nsd Ubuntu Pro 22.04 LTS 4.3.9-1ubuntu0.1~esm1
  • nsd Ubuntu Pro 24.04 LTS 4.8.0-1ubuntu0.1~esm1
  • nsd Ubuntu Pro 26.04 LTS 4.14.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-12246

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nsd openSUSE Leap 16.0 4.14.3-bp160.1.1
  • nsd openSUSE Tumbleweed 4.14.3-1.1

opensuse advisories openSUSE-SU-2026:21502-1openSUSE-SU-2026:11395-1

  • nsd Alpine 3.24 4.14.3-r0

alpine advisories ALPINE-CVE-2026-12246

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-2026-12246 updated cvss 8.0

nsd: Out of bounds stack write with crafted APL RR

  • 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
4 mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Affected products

  • NLnet Labs NSD

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input
  • CWE-20 Improper Input Validation

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.