vciy

CVE-2026-81642

INDEX BUILT · 2026-09-20

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Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY

CVE-2026-816423 of 4 sources documented this
38

rank 38 = 15 + 23 + 0 + 0 + 0

rank@v1 · scheduled

Someone is already using it

CISA KEV catalog · public proof-of-concept · FIRST EPSS

EPSS 0.00521  ·  without this subject the record ranks 23

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 9.1, from the CNA  ·  without this subject the record ranks 15

It is getting worse, not staying still

FIRST EPSS series, rescorings and bad loads removed

no persisting rise in 365 days  ·  without this subject the record ranks 38

How much of the world it touches

NVD CPE configurations

0 products in the CPE ranges  ·  without this subject the record ranks 38

Someone else already set the date

CISA KEV remediation due date

no CISA due date  ·  without this subject the record ranks 38

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$26,000over the next 30 days, if this record is yours
Movementnot heldno dated series to read a change from
Basisassumeda published average, not your estate

$26,000 = $4.99M incident cost x 1 exposure x 0.00521 likelihood

udv@v1 · unaudited · wrong for you until you say what you run

$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.

Hindsight · the state

0.00521EPSSNOT IN KEVas of 2026-09-20
Severity9.1 CRITICALreceipt
Harmtotal loss · unauthenticatedreceipt
Exploitationpublic proof-of-conceptreceipt
Defensefix version namedreceipt
Movementone observationreceipt
SINGLE READINGOne observation held. There is no shape yet. arc-rules@v1

Foresight · where to check next

Microsoft WindowsMicrosoft WindowsFortinetFortinetLinux81642

This record is one instance of CWE-122, heap-based buffer overflow. The index holds 3216 prior instances of this class, 20 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1

Full pattern panel

Prior records in this weakness class. Each is its own record, dated and receipted.
Color is a claim, not decoration:the hostile worldthe defenseno signal

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Harm, if it fires from the vector and the weakness

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Reachnetwork-reachable · no privileges required · no user interaction · low attack complexity · no attack requirementsreceipt
ImpactComplete confidentiality, integrity and availability loss, with impact on subsequent systemsreceipt
Scored fromCVSS v4.0 · the CNA's vectorreceipt
Weakness classCWE-122 Heap-based Buffer Overflowreceipt
Published consequencesCWE-122: Availability: DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory); Integrity, Confidentiality, Availability, Access Control: Execute…[email protected]

CISA KEV & Federal Remediation Deadline from the record and CISA

The fix, and how long it's been waiting.

Fixed in1.26.1receipt
Patch available sinceNo dated patch-availability record in held sources. The index holds reference URLs without dates and only the current revision of the CVE record, so the day a fix first existed cannot be derived. Only the versions it landed in.

Exploit Status & Known PoCs a ladder, not a score

Current rung: Proof-of-concept published · 1 public repository, 2026-09-18.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 1 public repository2026-09-18receipt
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, the CNA9.1 CRITICALreceipt
Exploit probability0.00521 · top 57% of all CVEsreceipt
Assigned byNLnet Labsreceipt
Recorded changes4 · last 19 Sep 2026derived

Affected & Fixed Versions as published

Affected productNLnet Labs Unboundreceipt
Fixed in1.26.1receipt

A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.

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What it is stated by the CNA

In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA can overflow the digest buffer. Remote code execution is possible through attacker controlled data. An adversary can exploit the vulnerability by controlling a malicious zone and querying a vulnerable Unbound. receipt

NVD's analysis a second authority

weakness
CWE-122
also scored by
[email protected] 9.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/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:Red

check it yourself nlnetlabs.nl receipt

Movement

Only one observation of this value is held, so there is no movement to show yet.

The full biography

Published2026-09-16Public PoC2026-09-18Index as of2026-09-18

The record had been public for 2 days when this index was last written.

Published 2026-09-16 receipt · Public PoC 2026-09-18 receipt · Index as of 2026-09-18 derived

The pattern, elsewhere

This record is one instance of CWE-122, heap-based buffer overflow. The index holds 3216 prior instances of this class, 20 KEV-listed. The nearest of its KEV-listed records are drawn beside this. [email protected]

CVE-2024-30051 · Microsoft Windows 10 Version 1809only 1 attribute comparableKEV listed · 2024receipt
CVE-2023-23376 · Microsoft Windows 10 Version 1507only 1 attribute comparableKEV listed · 2023receipt
CVE-2023-27997 · Fortinet FortiOS-6K7Konly 1 attribute comparableKEV listed · 2023receipt
CVE-2023-28252 · Microsoft Windows 10 Version 1809only 1 attribute comparableKEV listed · 2023receipt
CVE-2025-25249 · Fortinet FortiSwitchManageronly 1 attribute comparableKEV listed · 2026receipt
CVE-2026-53362 · Linuxonly 1 attribute comparableKEV listed · 2026receipt

"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1

3216 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.

No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.

Siblings and hubs

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What usually comes next

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