CVE-2026-32792Network attack vector

Remote crash via unbounded DNSCrypt marker scan

Published May 20, 2026 · Updated May 20, 2026

Out-of-bounds read in DNSCrypt handling in NLnet Labs Unbound 1.6.2 through 1.25.0 allows remote attackers to crash the resolver. The DNSCrypt packet reader scans decrypted plaintext past its buffer when an all-zero query omits the expected 0x80 marker, and a heap over-read can end in a process crash. Exposure requires a build compiled with --enable-dnscrypt and an enabled DNSCrypt listener; ordinary DNS service without that build option is unaffected.

CVSS severity5.3
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in DNSCrypt handling in NLnet Labs Unbound 1.6.2 through 1.25.0 allows remote attackers to crash the resolver. The DNSCrypt packet reader scans decrypted plaintext past its buffer when an all-zero query omits the expected 0x80 marker, and a heap over-read can end in a process crash. Exposure requires a build compiled with --enable-dnscrypt and an enabled DNSCrypt listener; ordinary DNS service without that build option is unaffected.

The record

CVE
CVE-2026-32792
Published
May 20, 2026
Updated
May 20, 2026
Vendor
NLnet Labs
Product
Unbound
Classifications
CWE-166, CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.6.2 <1.25.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NLnet Labs · Unboundversion=1.6.2 <1.25.1

Published CVSS scores

4.6NLnet LabsCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-166Improper Handling of Missing Special Element
CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation DoS

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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