vciy

CVE-2026-99999

INDEX BUILT · 2026-10-18

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ipv4: validate checksum_start before completing checksum

CVE-2026-999993 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 0.00211  ·  without this subject the record ranks 23

What it costs you if it fires

NVD CVSS base score, then the CNA's own

CVSS 9.3, 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

Hindsight · the state

0.00211EPSSNOT IN KEVas of 2026-10-18
Severity9.3 CRITICALreceipt
Harmtotal lossreceipt
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

No weakness class or product neighbourhood is held for this record, so this index cannot name anywhere to check next. That is an absence in the record, not a finding about the software.

Color is a claim, not decoration:the hostile worldthe defenseno signal

Running Linux? Check your version

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What counts as a move

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Harm, if it fires from the vector and the weakness

Written for the ticket you're about to file.

Reachneeds local access · no privileges required · no user interaction · low attack complexityreceipt
ImpactComplete confidentiality, integrity and availability loss, with impact beyond the vulnerable componentreceipt
Scored fromCVSS v3.1 · the CNA's vectorreceipt
Weakness classNo CWE mapping in held sources.

CISA KEV & Federal Remediation Deadline from the record and CISA

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

Fixed in5.10.272; 5.15.223; 6.1.190; 6.6.159; 6.12.113; 6.18.57; 7.2.11receipt
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.
BOD 26-04 deadlineIf the system is reachable from the internet: 14 days. If not: fix at the next system upgrade.derived
Show full BOD 26-04 deadline

CISA scored it on 16 Oct 2026: automatable no, technical impact total. Calendar days from the KEV listing or from when you find it on a system, whichever is first. Federal agencies are bound from 7 Dec 2026, and contracts often carry it to suppliers. The directive and its table

Exploit Status & Known PoCs a ladder, not a score

Current rung: Proof-of-concept published · 1 public repository, 2026-10-16.

  • RUNG 1Nothing observed in held sources
  • RUNG 2Proof-of-concept published · 1 public repository2026-10-16receipt
  • RUNG 3Exploited in the wild · CISA KEV listed
  • RUNG 4Ransomware campaign use known

Authority who says so

CVSS, the CNA9.3 CRITICALreceipt
Exploit probability0.00211 · top 89% of all CVEsreceipt
Assigned byLinuxreceipt
Recorded changes4 · last 18 Oct 2026derived

Affected & Fixed Versions as published

Affected productLinuxreceipt
Fixed in5.10.272; 5.15.223; 6.1.190; 6.6.159; 6.12.113; 6.18.57; 7.2.11receipt

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.

Unaudited dollar value2 of 3 inputs carry a receipt
Exposure$10,500over the next 30 days, if this record is yours
Movementnot heldno dated series to read a change from
Basisassumeda published average, not your estate

$10,500 = $4.99M incident cost x 1 exposure x 0.00211 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.

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What it is stated by the CNA

In the Linux kernel, the following vulnerability has been resolved: ipv4: validate checksum_start before completing checksum If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of mischief. This was discovered and reported by Paulos, and has been reporoduced by others independently since. We really shouldn't allow such packets in, but as a defence in depth measure, let's also check before we complete the checksum. A more complete validation at input is forthcoming, but needs more work. receipt

check it yourself git.kernel.org git.kernel.org git.kernel.org git.kernel.org git.kernel.org git.kernel.org +4 morereceipt

Movement

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

The full biography

Published2026-10-15Public PoC2026-10-16Index as of2026-10-16

The record had been public for 1 day when this index was last written.

Published 2026-10-15 receipt · Public PoC 2026-10-16 receipt · Index as of 2026-10-16 derived

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What usually comes next

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