CVE-2026-98491
Received
Received - Intake
Use-After-Free in Linux Kernel Open vSwitch Conntrack
Vulnerability report for CVE-2026-98491, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | cae3a2627520c3795b54533c5328b77af3405dbe |
| Linux | Linux | 4.3 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
