CVE-2026-53223

High

In the Linux kernel, the following vulnerability has been resolved: net: guard timestamp cmsgs to real error queue skbs skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb from sk_error_queue. That assumption is not true for AF_PACKET sockets: outgoing packet taps are also delivered to packet sockets with skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET instead of struct sock_exterr_skb. If such an skb is received with timestamping enabled, the generic timestamp cmsg path can read AF_PACKET control-buffer state as sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop counter overlaps opt_stats. An odd drop count makes the path emit SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear skbs this copies past the linear head and can trigger hardened usercopy or disclose adjacent heap contents. Keep skb_is_err_queue() local to net/socket.c, but make it verify that the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal receive ownership and no longer pass as error-queue skbs, while legitimate sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free ownership.

Package Linux Kernel
Published 2026-06-25
Last modified 2026-07-02
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.1

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected versions

Linux kernel versions 4.10.14, 4.11 and later are affected. Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13, 7.1 and their respective stable series.

Affected from
≥ 4.10.14 ≥ 4.11
Fixed in
✓ 5.10.259 5.10.x ✓ 5.15.210 5.15.x ✓ 6.1.176 6.1.x ✓ 6.6.143 6.6.x ✓ 6.12.94 6.12.x ✓ 6.18.36 6.18.x ✓ 7.0.13 7.0.x ✓ 7.1

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-53223?

    CVE-2026-53223 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 . It affects Linux kernel versions from 4.10.14 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-53223 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-53223?

    CVE-2026-53223 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H .

  • Is there a patch available for CVE-2026-53223?

    Yes. CVE-2026-53223 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 4.10.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-53223 actively exploited?

    No. CVE-2026-53223 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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