CyberSecBulletin
CVE-2025-38146NVD status: Modified

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2025-38146 is a high-severity improper validation of array index vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 4b9a086eedc1fddae632310386098c12155e3d0a, ad17eb86d042d72a59fd184ad1adf34f5eb36843, f26fe7c3002516dd3c288f1012786df31f4d89e0 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 0.49% 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 4b9a086eedc1fddae632310386098c12155e3d0a or ad17eb86d042d72a59fd184ad1adf34f5eb36843 or f26fe7c3002516dd3c288f1012786df31f4d89e0 or 8ebcd311b4866ab911d1445ead08690e67f0c488, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.239 or 5.15.186 or 6.1.142 or 6.6.94, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxfbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, 4b9a086eedc1fddae632310386098c12155e3d0a; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, ad17eb86d042d72a59fd184ad1adf34f5eb36843; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, f26fe7c3002516dd3c288f1012786df31f4d89e0; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, 8ebcd311b4866ab911d1445ead08690e67f0c488; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, 69541e58323ec3e3904e1fa87a6213961b1f52f4; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, 3c1906a3d50cb94fd0a10e97a1c0a40c0f033cb7; fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3 up to, but not including, 0bdc924bfb319fb10d1113cbf091fc26fb7b1f99; 5.54b9a086eedc1fddae632310386098c12155e3d0a, ad17eb86d042d72a59fd184ad1adf34f5eb36843, f26fe7c3002516dd3c288f1012786df31f4d89e0, 8ebcd311b4866ab911d1445ead08690e67f0c488, 69541e58323ec3e3904e1fa87a6213961b1f52f4, 3c1906a3d50cb94fd0a10e97a1c0a40c0f033cb7
LinuxLinux Kernel5.5 up to, but not including, 5.10.239; 5.11 up to, but not including, 5.15.186; 5.16 up to, but not including, 6.1.142; 6.2 up to, but not including, 6.6.94; 6.7 up to, but not including, 6.12.34; 6.13 up to, but not including, 6.15.35.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, 6.15.3
DebianDebian Linux11.0Not stated

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
HighData or code can be modified at will.
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:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.4CriticalCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: Fix the dead loop of MPLS parse The unexpected MPLS packet may not end with the bottom label stack. When there are many stacks, The label count value has wrapped around. A dead loop occurs, soft lockup/CPU stuck finally. stack backtrace: UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26 index -1 is out of range for type '__be32 [3]' CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021 Call Trace: <IRQ> show_stack+0x52/0x5c dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_out_of_bounds.cold+0x44/0x49 key_extract_l3l4+0x82a/0x840 [openvswitch] ? kfree_skbmem+0x52/0xa0 key_extract+0x9c/0x2b0 [openvswitch] ovs_flow_key_extract+0x124/0x350 [openvswitch] ovs_vport_receive+0x61/0xd0 [openvswitch] ? kernel_init_free_pages.part.0+0x4a/0x70 ? get_page_from_freelist+0x353/0x540 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23a/0xf00 __netif_receive_skb_list_core+0xfa/0x240 netif_receive_skb_list_internal+0x18e/0x2a0 napi_complete_done+0x7a/0x1c0 bnxt_poll+0x155/0x1c0 [bnxt_en] __napi_poll+0x30/0x180 net_rx_action+0x126/0x280 ? bnxt_msix+0x67/0x80 [bnxt_en] handle_softirqs+0xda/0x2d0 irq_exit_rcu+0x96/0xc0 common_interrupt+0x8e/0xa0 </IRQ>

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

The underlying weakness: Improper Validation of Array Index

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How developers prevent this class of flaw

  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
  • Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.

More Improper Validation of Array Index vulnerabilities (CWE-129)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Validation of Array Index vulnerabilities

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