High 7.1Published Jun 25, 2026

CVE-2026-53223net: guard timestamp cmsgs to real error queue skbs

Updated under an hour ago (Oct 27, 2026, 11:50 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): CWE-125
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	8605330aac5a5785630aec8f64378a54891937cc builds before 24a0d548d3a765cd4558224e4f8e06e14cba26e3; 8605330aac5a5785630aec8f64378a54891937cc builds before 71ff5cdd5da61d0438e902aa0fd68c28bc901abe; from 8605330aac5a5785630aec8f64378a54891937cc before ad9a0374ee6d11048e1f74cd5180bad58b9848b4; from 8605330aac5a5785630aec8f64378a54891937cc before b903e9b5629ec8dd6db92174070045bf81ad7060; from 8605330aac5a5785630aec8f64378a54891937cc before e0665b2a8e90bb08bd205062c75662b502d31797; 8605330aac5a5785630aec8f64378a54891937cc builds before 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31; from 8605330aac5a5785630aec8f64378a54891937cc before eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a; 8605330aac5a5785630aec8f64378a54891937cc builds before 1ee90b77b727df903033db873c75caac5c27ec98; and 2 more ranges	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 4.10.14 before 4.11; from 4.11.1 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.94; from 6.13 before 6.18.36; from 6.19 before 7.0.13; and 13 more ranges	NVD

References

References

https://git.kernel.org/stable/c/24a0d548d3a765cd4558224e4f8e06e14cba26e3	patch
https://git.kernel.org/stable/c/71ff5cdd5da61d0438e902aa0fd68c28bc901abe	patch
https://git.kernel.org/stable/c/ad9a0374ee6d11048e1f74cd5180bad58b9848b4	patch
https://git.kernel.org/stable/c/b903e9b5629ec8dd6db92174070045bf81ad7060	patch
https://git.kernel.org/stable/c/e0665b2a8e90bb08bd205062c75662b502d31797	patch
https://git.kernel.org/stable/c/3dde4fb941fa5649ab809f6cd3e20e0c424a4e31	patch
https://git.kernel.org/stable/c/eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a	patch
https://git.kernel.org/stable/c/1ee90b77b727df903033db873c75caac5c27ec98	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.