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VulnerabilityPublished

CVE-2026-32792: NLnet Labs Unbound · Improper Handling of Missing Special Element

Affects NLnet Labs UnboundSource CVE Database V5

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Not known to be exploited · CVSS 4.6 Medium : upgrade to 1.25.1 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score
4.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.25.1
CVSS: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/U:Green

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade NLnet Labs Unbound to 1.25.1.

Affected software

ProductAffectedFixed in
NLnet LabsUnboundAffected
  • >=1.6.2 <1.25.1
Fixed in
  • 1.25.1
Nlnetlabsnlnetlabs/unboundpkg:deb/nlnetlabs/unboundOther threatsAffected
  • =1.6.2
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade to Unbound version 1.25.1 or later, which contains an official fix bounding the DNSCrypt packet reading to prevent heap overflow. No other mitigations are indicated. Patch status is confirmed by the vendor advisory stating the fix is included in version 1.25.1.

Description

NLnet Labs Unbound versions 1.6.2 through 1.25.0 have a denial of service vulnerability when compiled with DNSCrypt support. A specially crafted DNSCrypt query with decrypted plaintext of all zero bytes and missing an expected marker can cause Unbound to read beyond the intended buffer, potentially causing a heap overflow and crash. The likelihood of a crash is low and depends on the memory allocator and layout. Version 1.25.1 includes a patch that bounds the reading to prevent this issue.

References

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