CyberSecBulletin
CVE-2026-53223NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-53223 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 24a0d548d3a765cd4558224e4f8e06e14cba26e3, 71ff5cdd5da61d0438e902aa0fd68c28bc901abe, ad9a0374ee6d11048e1f74cd5180bad58b9848b4 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.14% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 24a0d548d3a765cd4558224e4f8e06e14cba26e3 or 71ff5cdd5da61d0438e902aa0fd68c28bc901abe or ad9a0374ee6d11048e1f74cd5180bad58b9848b4 or b903e9b5629ec8dd6db92174070045bf81ad7060, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.11 or 5.10.259 or 5.15.210 or 6.1.176, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux8605330aac5a5785630aec8f64378a54891937cc up to, but not including, 24a0d548d3a765cd4558224e4f8e06e14cba26e3; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, 71ff5cdd5da61d0438e902aa0fd68c28bc901abe; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, ad9a0374ee6d11048e1f74cd5180bad58b9848b4; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, b903e9b5629ec8dd6db92174070045bf81ad7060; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, e0665b2a8e90bb08bd205062c75662b502d31797; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a; 8605330aac5a5785630aec8f64378a54891937cc up to, but not including, 1ee90b77b727df903033db873c75caac5c27ec98; and 3 more ranges24a0d548d3a765cd4558224e4f8e06e14cba26e3, 71ff5cdd5da61d0438e902aa0fd68c28bc901abe, ad9a0374ee6d11048e1f74cd5180bad58b9848b4, b903e9b5629ec8dd6db92174070045bf81ad7060, e0665b2a8e90bb08bd205062c75662b502d31797, 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)V3.1.6 and later; V3.1.7 and laterNot stated
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)V3.1.6 and later; V3.1.7 and laterNot stated
LinuxLinux Kernel4.10.14 up to, but not including, 4.11; 4.11.1 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; and 2 more ranges4.11, 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by CNA.

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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