CVE-2026-98873

netfilter: nf_conntrack_expect: zero at allocation time

Published Oct 23, 2026 CVSS 3.1 · 3.3 Low EPSS < 1% KEV · Not listed

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_expect: zero at allocation time

There are occasional LLM hints wrt. leaking uninitialized data to
userspace via ctnetlink. Just zero at allocation time,
expectations are not frequently used these days.

Intentionally keeps _init as-is because we could theoretically
support re-init, so add the missing exp->dir there.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< 39cb6ff947c16a576ea68c5f272e634acdcb0085
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< 90545aa07a183887e9d72ce573c18e08f62e2c91
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< 9c11d7ea5ff4dbe162e79f00188814ef5483c295
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< b7f3ee925aee9f1f547d539bc03c35433c238958
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< 824397af7bfe14edad374c64253dae0187ca623d
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< a39ecb856514274c80d0fac4d128dba6b266a8ed
`076a0ca02644657b13e4af363f487ced2942e9cb`	affected	< 241ccd2fed9051db443aadce248fc0ab30f55e97

Linux

affected

Version	Status	Constraints
`3.4`	affected	—
`0`	unaffected	< 3.4
`5.10.271`	unaffected	≤ 5.10.*
`5.15.222`	unaffected	≤ 5.15.*
`6.1.189`	unaffected	≤ 6.1.*
`6.6.158`	unaffected	≤ 6.6.*
`6.12.111`	unaffected	≤ 6.12.*
`6.18.53`	unaffected	≤ 6.18.*
`7.2`	unaffected	≤ *

No data.

Vendor Product Versions

Linux

Version	Status	Scheme	Platform
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,39cb6ff947c16a576ea68c5f272e634acdcb0085)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,90545aa07a183887e9d72ce573c18e08f62e2c91)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,9c11d7ea5ff4dbe162e79f00188814ef5483c295)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,b7f3ee925aee9f1f547d539bc03c35433c238958)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,824397af7bfe14edad374c64253dae0187ca623d)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,a39ecb856514274c80d0fac4d128dba6b266a8ed)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,241ccd2fed9051db443aadce248fc0ab30f55e97)`	affected	code_commit	—
`[0,5.10.271)`	affected	semver	—
`[0,5.15.222)`	affected	semver	—
`[0,6.1.189)`	affected	semver	—
`[0,6.6.158)`	affected	semver	—
`[0,6.12.111)`	affected	semver	—
`[0,6.18.53)`	affected	semver	—

Linux

Version	Status	Scheme	Platform
`[5.10.271,5.11.0)`	unaffected	semver	—
`[5.15.222,5.16.0)`	unaffected	semver	—
`[6.1.189,6.2.0)`	unaffected	semver	—
`[6.6.158,6.7.0)`	unaffected	semver	—
`[6.12.111,6.13.0)`	unaffected	semver	—
`[6.18.53,6.19.0)`	unaffected	semver	—
`[7.2,*]`	unaffected	generic	—

Linux

Linux Kernel

Version	Status	Scheme	Platform
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,39cb6ff947c16a576ea68c5f272e634acdcb0085)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,90545aa07a183887e9d72ce573c18e08f62e2c91)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,9c11d7ea5ff4dbe162e79f00188814ef5483c295)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,b7f3ee925aee9f1f547d539bc03c35433c238958)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,824397af7bfe14edad374c64253dae0187ca623d)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,a39ecb856514274c80d0fac4d128dba6b266a8ed)`	affected	code_commit	—
`[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,241ccd2fed9051db443aadce248fc0ab30f55e97)`	affected	code_commit	—
`[0,5.10.271)`	affected	semver	—
`[0,5.15.222)`	affected	semver	—
`[0,6.1.189)`	affected	semver	—
`[0,6.6.158)`	affected	semver	—
`[0,6.12.111)`	affected	semver	—
`[0,6.18.53)`	affected	semver	—

Linux

Linux Kernel

Version	Status	Scheme	Platform
`[5.10.271,5.11.0)`	unaffected	semver	—
`[5.15.222,5.16.0)`	unaffected	semver	—
`[6.1.189,6.2.0)`	unaffected	semver	—
`[6.6.158,6.7.0)`	unaffected	semver	—
`[6.12.111,6.13.0)`	unaffected	semver	—
`[6.18.53,6.19.0)`	unaffected	semver	—
`[7.2,*]`	unaffected	generic	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Ubuntu USN	USN-8961-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9019-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9020-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9022-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9023-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9024-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9025-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9026-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9029-1	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-9039-1	Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN	USN-9040-1	Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN	USN-9066-1	Linux kernel (HWE) vulnerabilities
Ubuntu USN	USN-9091-1	Linux kernel (NVIDIA Tegra) vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.179% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98873.mbox
https://git.kernel.org/stable/c/241ccd2fed9051db443aadce248fc0ab30f55e97
https://git.kernel.org/stable/c/39cb6ff947c16a576ea68c5f272e634acdcb0085
https://git.kernel.org/stable/c/824397af7bfe14edad374c64253dae0187ca623d
https://git.kernel.org/stable/c/90545aa07a183887e9d72ce573c18e08f62e2c91
https://git.kernel.org/stable/c/9c11d7ea5ff4dbe162e79f00188814ef5483c295
https://git.kernel.org/stable/c/a39ecb856514274c80d0fac4d128dba6b266a8ed
https://git.kernel.org/stable/c/b7f3ee925aee9f1f547d539bc03c35433c238958
https://nvd.nist.gov/vuln/detail/CVE-2026-98873
https://www.cve.org/CVERecord?id=CVE-2026-98873

History

Oct 26, 2026 2:15 PM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses	CWE-200 CWE-560

Oct 26, 2026 12:15 PM Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-908
References		https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98873.mbox https://nvd.nist.gov/vuln/detail/CVE-2026-98873 https://www.cve.org/CVERecord?id=CVE-2026-98873
Metrics	threat_severity `None`	cvssV3_1 `{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}` threat_severity `Low`

Oct 23, 2026 6:00 PM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-200 CWE-560

Oct 23, 2026 2:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Linux linux
Vendors & Products		Linux linux

Oct 23, 2026 12:00 PM Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references View changes

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: zero at allocation time There are occasional LLM hints wrt. leaking uninitialized data to userspace via ctnetlink. Just zero at allocation time, expectations are not frequently used these days. Intentionally keeps _init as-is because we could theoretically support re-init, so add the missing exp->dir there.
Title		netfilter: nf_conntrack_expect: zero at allocation time
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/241ccd2fed9051db443aadce248fc0ab30f55e97 https://git.kernel.org/stable/c/39cb6ff947c16a576ea68c5f272e634acdcb0085 https://git.kernel.org/stable/c/824397af7bfe14edad374c64253dae0187ca623d https://git.kernel.org/stable/c/90545aa07a183887e9d72ce573c18e08f62e2c91 https://git.kernel.org/stable/c/9c11d7ea5ff4dbe162e79f00188814ef5483c295 https://git.kernel.org/stable/c/a39ecb856514274c80d0fac4d128dba6b266a8ed https://git.kernel.org/stable/c/b7f3ee925aee9f1f547d539bc03c35433c238958