CVE-2026-53223
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Modified
Affected
- Linux Kernel < 4.11
- Linux Kernel < 5.10.259
- Linux Kernel < 5.15.210
- Linux Kernel < 6.1.176
- Linux Kernel < 6.6.143
- Linux Kernel < 6.12.94
- Linux Kernel < 6.18.36
- Linux Kernel < 7.0.13
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-53223.md and follow it. Check whether this project is affected by CVE-2026-53223. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/1ee90b77b727df903033db873c75caac5c27ec98
- https://git.kernel.org/stable/c/24a0d548d3a765cd4558224e4f8e06e14cba26e3
- https://git.kernel.org/stable/c/3dde4fb941fa5649ab809f6cd3e20e0c424a4e31
- https://git.kernel.org/stable/c/71ff5cdd5da61d0438e902aa0fd68c28bc901abe
- https://git.kernel.org/stable/c/ad9a0374ee6d11048e1f74cd5180bad58b9848b4
- https://git.kernel.org/stable/c/b903e9b5629ec8dd6db92174070045bf81ad7060
- https://git.kernel.org/stable/c/e0665b2a8e90bb08bd205062c75662b502d31797
- https://git.kernel.org/stable/c/eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a
References
- https://git.kernel.org/stable/c/1ee90b77b727df903033db873c75caac5c27ec98
- https://git.kernel.org/stable/c/24a0d548d3a765cd4558224e4f8e06e14cba26e3
- https://git.kernel.org/stable/c/3dde4fb941fa5649ab809f6cd3e20e0c424a4e31
- https://git.kernel.org/stable/c/71ff5cdd5da61d0438e902aa0fd68c28bc901abe
- https://git.kernel.org/stable/c/ad9a0374ee6d11048e1f74cd5180bad58b9848b4
- https://git.kernel.org/stable/c/b903e9b5629ec8dd6db92174070045bf81ad7060
- https://git.kernel.org/stable/c/e0665b2a8e90bb08bd205062c75662b502d31797
- https://git.kernel.org/stable/c/eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html