High

CVE-2026-98491 — net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry In a case where skb with an unconfirmed ct entry gets cloned, we may end up committing both but with different sets of extensions. The series of events: 1. The first clone wants to commit and runs the helpers wiring up the extension pointer into the expectation list. 2. Then it looses the confirmation keeping the entry unconfirmed. 3. Second clone now wants to commit labels and adds the new extension for that breaking the pointer in the expectation list causing UAF on the destruction path later. While this is possible to trigger, there should be no practical network pipeline where committing both clones without modifications into the same zone is needed. So, let's just reset the entry in case for some reason we got an skb with a shared one during commit. This doesn't affect any known use cases, but avoids any potential problems with sharing and modification of the unconfirmed ct entry. The fixes tag points to the introduction of helpers, since that's the main UAF trigger for the sharing.

Published Oct 18, 2026 · Updated Oct 24, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.17%

ahead of 6% of scored CVEs · Oct 30, 2026

Affects

Linux

CVSS base

7.8

High · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ cae3a2627520c3795b54533c5328b77af3405dbe and < e0fa5ea434b7e8467ef3adc64e3858b1ca2a642d≥ cae3a2627520c3795b54533c5328b77af3405dbe and < 37e3c878b183a115f9a114067f9ef3b408ad27fb≥ cae3a2627520c3795b54533c5328b77af3405dbe and < 707c2dc77891a874f4e8c52c285a511079164ec8≥ cae3a2627520c3795b54533c5328b77af3405dbe and < de41ee24f77b0fc45397db3e277cae2adbd43dfe≥ cae3a2627520c3795b54533c5328b77af3405dbe and < 55e5256adf3940e71802e2f749cacf81518726b0≥ cae3a2627520c3795b54533c5328b77af3405dbe and < e2829ae5459ddb5fce526b2e84697edf6c0c3cef≥ cae3a2627520c3795b54533c5328b77af3405dbe and < 457e0df1b5711fbeb7ba1b6bfd826f5ef30e7e55≥ cae3a2627520c3795b54533c5328b77af3405dbe and < 26b2bd70d22457556e2fa01cbf1192cb1a94d619 and 1 more version 4.3	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

EPSS over time FIRST

Oct 19, 2026 → Oct 30, 2026 · 12 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
CVSS changed · 7.8
Oct 24, 2026 · NIST National Vulnerability Database
Record published
Oct 18, 2026
Affected products added · linux/linux
Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 18, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 18, 2026 · NIST National Vulnerability Database
CVE published
Oct 18, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 24, 2026 – Oct 24, 2026
1× Official description updated · Oct 18, 2026 – Oct 18, 2026

References

10 on the record

git.kernel.org/stable/c/e0fa5ea434b7e8467ef3adc64e3858b1ca2a642d
NIST National Vulnerability Database
git.kernel.org/stable/c/de41ee24f77b0fc45397db3e277cae2adbd43dfe
NIST National Vulnerability Database
git.kernel.org/stable/c/26b2bd70d22457556e2fa01cbf1192cb1a94d619
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-98491
GitHub Security Advisories
git.kernel.org/stable/c/707c2dc77891a874f4e8c52c285a511079164ec8
NIST National Vulnerability Database
git.kernel.org/stable/c/457e0df1b5711fbeb7ba1b6bfd826f5ef30e7e55
NIST National Vulnerability Database
git.kernel.org/stable/c/37e3c878b183a115f9a114067f9ef3b408ad27fb
NIST National Vulnerability Database
git.kernel.org/stable/c/e2829ae5459ddb5fce526b2e84697edf6c0c3cef
NIST National Vulnerability Database
github.com/advisories/GHSA-xf3m-wp4c-wrgw
GitHub Security Advisories
git.kernel.org/stable/c/55e5256adf3940e71802e2f749cacf81518726b0
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

High CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 3d
Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 3d
Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 3d
Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 3d
Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 3d
Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 3d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-98491 is "net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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