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CVE-2025-39883NVD status: Analyzed

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2025-39883 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 8e01ea186a52c90694c08a9ff57bea1b0e78256a, fb65803ccff37cf9123c50c1c02efd1ed73c4ed5, 99f7048957f5ae3cee1c01189147e73a9a96de02 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 0.16% 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 8e01ea186a52c90694c08a9ff57bea1b0e78256a or fb65803ccff37cf9123c50c1c02efd1ed73c4ed5 or 99f7048957f5ae3cee1c01189147e73a9a96de02 or e4ec6def5643a1c9511115b3884eb879572294c6, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.300 or 5.10.245 or 5.15.194 or 6.1.153, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, 8e01ea186a52c90694c08a9ff57bea1b0e78256a; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, fb65803ccff37cf9123c50c1c02efd1ed73c4ed5; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, 99f7048957f5ae3cee1c01189147e73a9a96de02; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, e4ec6def5643a1c9511115b3884eb879572294c6; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, 3d278e89c2ea62b1aaa4b0d8a9766a35b3a3164a; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, 7618fd443aa4cfa553a64cacf5721581653ee7b0; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, 63a327a2375a8ce7a47dec5aaa4d8a9ae0a00b96; f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe up to, but not including, d613f53c83ec47089c4e25859d5e8e0359f6f8da; and 1 more ranges8e01ea186a52c90694c08a9ff57bea1b0e78256a, fb65803ccff37cf9123c50c1c02efd1ed73c4ed5, 99f7048957f5ae3cee1c01189147e73a9a96de02, e4ec6def5643a1c9511115b3884eb879572294c6, 3d278e89c2ea62b1aaa4b0d8a9766a35b3a3164a, 7618fd443aa4cfa553a64cacf5721581653ee7b0
LinuxLinux Kernel4.13 up to, but not including, 5.4.300; 5.5 up to, but not including, 5.10.245; 5.11 up to, but not including, 5.15.194; 5.16 up to, but not including, 6.1.153; 6.2 up to, but not including, 6.6.107; 6.7 up to, but not including, 6.12.48; 6.13 up to, but not including, 6.16.8; 6.175.4.300, 5.10.245, 5.15.194, 6.1.153, 6.6.107, 6.12.48
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
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 NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory When I did memory failure tests, below panic occurs: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) kernel BUG at include/linux/page-flags.h:616! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Call Trace: <TASK> unpoison_memory+0x2f3/0x590 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xd5/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f0314887 RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 </TASK> Modules linked in: hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- The root cause is that unpoison_memory() tries to check the PG_HWPoison flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is triggered. This can be reproduced by below steps: 1.Offline memory block: echo offline > /sys/devices/system/memory/memory12/state 2.Get offlined memory pfn: page-types -b n -rlN 3.Write pfn to unpoison-pfn echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn This scenario can be identified by pfn_to_online_page() returning NULL. And ZONE_DEVICE pages are never expected, so we can simply fail if pfn_to_online_page() == NULL to fix the bug.

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

Third-party and government advisories

Recent Out-of-bounds Read vulnerabilities

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