CVE-2026-98322

Uninitialized kernel data use via IPv4 netmap

Published Oct 6, 2026 · Updated Oct 6, 2026

Uninitialized memory use in Linux kernel netfilter allows attackers to pass stale stack bytes into IPv4 netmap NAT setup. The nft_nat_setup_netmap() function initializes only the four-byte IPv4 member of a 16-byte stack union, then copies the full union into NAT address ranges consumed by nf_nat_setup_info(). The path requires an IPv4 nftables NAT rule using NETMAP and traffic through that rule; the published report establishes a KMSAN uninitialized-value finding, not a demonstrated leak or crash.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized memory use in Linux kernel netfilter allows attackers to pass stale stack bytes into IPv4 netmap NAT setup. The nft_nat_setup_netmap() function initializes only the four-byte IPv4 member of a 16-byte stack union, then copies the full union into NAT address ranges consumed by nf_nat_setup_info(). The path requires an IPv4 nftables NAT rule using NETMAP and traffic through that rule; the published report establishes a KMSAN uninitialized-value finding, not a demonstrated leak or crash.

The record

CVE
CVE-2026-98322
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=3ff7ddb1353da9b535e65702704cbadea1da9a00 <0ce42c7b84032335abff9eac43762e4ca8224451
  2. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <161f5860c92a8ec80b6bdff16e79d70dcd8afc5a
  3. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <1c43f5db482f74b41987c39c9c375a5e767556eb
  4. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <29365695842db0a97b701a43a09fad1b4f7ecf3e
  5. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <7b9380c38c2fd2189416fa602bdbc5c8523b84b2
  6. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <d313499df66159b4b7971d760d16729598ab7e5a
  7. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <e4982c489ee359162eee3ece1fb36082648464a5
  8. Affected versionversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <eb2030137dba3b59cbb5057a33af70488d6bc231
  9. Affected versionversion=5.8

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=3ff7ddb1353da9b535e65702704cbadea1da9a00 <0ce42c7b84032335abff9eac43762e4ca8224451; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <161f5860c92a8ec80b6bdff16e79d70dcd8afc5a; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <1c43f5db482f74b41987c39c9c375a5e767556eb; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <29365695842db0a97b701a43a09fad1b4f7ecf3e; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <7b9380c38c2fd2189416fa602bdbc5c8523b84b2; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <d313499df66159b4b7971d760d16729598ab7e5a; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <e4982c489ee359162eee3ece1fb36082648464a5; version=3ff7ddb1353da9b535e65702704cbadea1da9a00 <eb2030137dba3b59cbb5057a33af70488d6bc231; version=5.8

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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