Bug 2479832 (CVE-2026-46323) - CVE-2026-46323 kernel: Linux kernel: Use-After-Free in net/gro due to improper handling of zerocopy skbs
Summary: CVE-2026-46323 kernel: Linux kernel: Use-After-Free in net/gro due to imprope...
Keywords:
Status: NEW
Alias: CVE-2026-46323
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2479833
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-19 13:49 UTC by OSIDB Bzimport
Modified: 2026-07-28 13:48 UTC (History)
3 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:27708 0 None None None 2026-06-22 05:56:04 UTC
Red Hat Product Errata RHSA-2026:27731 0 None None None 2026-06-22 05:04:19 UTC
Red Hat Product Errata RHSA-2026:27735 0 None None None 2026-06-22 06:02:12 UTC
Red Hat Product Errata RHSA-2026:36018 0 None None None 2026-07-06 19:57:15 UTC
Red Hat Product Errata RHSA-2026:44259 0 None None None 2026-07-28 12:56:21 UTC
Red Hat Product Errata RHSA-2026:44262 0 None None None 2026-07-28 13:48:51 UTC
Red Hat Product Errata RHSA-2026:44270 0 None None None 2026-07-23 07:10:59 UTC

Description OSIDB Bzimport 2026-05-19 13:49:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: gro: don't merge zcopy skbs

skb_gro_receive() can currently copy frags between the source and GRO
skb, without checking the zerocopy status, and in particular the
SKBFL_MANAGED_FRAG_REFS flag.

When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference
on the pages in shinfo->frags. Appending those frags to another skb's
frags without fixing up the page refcount can lead to UAF.

When either the last skb in the GRO chain (the one we would append
frags to) or the source skb is zerocopy, don't merge the skbs.

This flaw is a variant of Fragnesia (CVE-2026-46300) which targets the same fundamental mechanism through GRO frag-merge.
Comment 2 Keith Grant 2026-06-09 13:21:00 UTC 
Updating comment#0 to reflect upstream report.
Comment 4 errata-xmlrpc 2026-06-22 05:04:18 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:27731 https://access.redhat.com/errata/RHSA-2026:27731
Comment 5 errata-xmlrpc 2026-06-22 05:56:03 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:27708 https://access.redhat.com/errata/RHSA-2026:27708
Comment 6 errata-xmlrpc 2026-06-22 06:02:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:27735 https://access.redhat.com/errata/RHSA-2026:27735
Comment 7 errata-xmlrpc 2026-07-06 19:57:14 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36018 https://access.redhat.com/errata/RHSA-2026:36018
Comment 10 errata-xmlrpc 2026-07-23 07:10:58 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:44270 https://access.redhat.com/errata/RHSA-2026:44270
Comment 11 errata-xmlrpc 2026-07-28 12:56:20 UTC 
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.20

Via RHSA-2026:44259 https://access.redhat.com/errata/RHSA-2026:44259
Comment 12 errata-xmlrpc 2026-07-28 13:48:50 UTC 
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.21

Via RHSA-2026:44262 https://access.redhat.com/errata/RHSA-2026:44262
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