CyberSecBulletin
CVE-2026-31488NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-31488 is a high-severity use after free 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 da1d0ed31e9802fd99384f43cc63678a5a11cb41, 21159d8b335a6b9f44cbb506733013a902ae2da4, 10862e344b4d6434642a48c87d765813fc0b0ba7 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 da1d0ed31e9802fd99384f43cc63678a5a11cb41 or 21159d8b335a6b9f44cbb506733013a902ae2da4 or 10862e344b4d6434642a48c87d765813fc0b0ba7 or 8a5edc97fd9c6415ff2eff872748439a97e3c3d8, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12.80 or 6.18.21 or 6.19.11, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, da1d0ed31e9802fd99384f43cc63678a5a11cb41; 17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, 21159d8b335a6b9f44cbb506733013a902ae2da4; 17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, 10862e344b4d6434642a48c87d765813fc0b0ba7; 17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, 8a5edc97fd9c6415ff2eff872748439a97e3c3d8; 17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, 111208b5b7ebcdadb3f922cc52d8425f0fa91b33; 17ce8a6907f77b7ac97ddaa071d8a1f6e06ce85b up to, but not including, aed3d041ab061ec8a64f50a3edda0f4db7280025; 5.18da1d0ed31e9802fd99384f43cc63678a5a11cb41, 21159d8b335a6b9f44cbb506733013a902ae2da4, 10862e344b4d6434642a48c87d765813fc0b0ba7, 8a5edc97fd9c6415ff2eff872748439a97e3c3d8, 111208b5b7ebcdadb3f922cc52d8425f0fa91b33, aed3d041ab061ec8a64f50a3edda0f4db7280025
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10.0 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update ServiceNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel5.18.1 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 5.18; 7.06.12.80, 6.18.21, 6.19.11

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 CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighCNA

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Do not skip unrelated mode changes in DSC validation Starting with commit 17ce8a6907f7 ("drm/amd/display: Add dsc pre-validation in atomic check"), amdgpu resets the CRTC state mode_changed flag to false when recomputing the DSC configuration results in no timing change for a particular stream. However, this is incorrect in scenarios where a change in MST/DSC configuration happens in the same KMS commit as another (unrelated) mode change. For example, the integrated panel of a laptop may be configured differently (e.g., HDR enabled/disabled) depending on whether external screens are attached. In this case, plugging in external DP-MST screens may result in the mode_changed flag being dropped incorrectly for the integrated panel if its DSC configuration did not change during precomputation in pre_validate_dsc(). At this point, however, dm_update_crtc_state() has already created new streams for CRTCs with DSC-independent mode changes. In turn, amdgpu_dm_commit_streams() will never release the old stream, resulting in a memory leak. amdgpu_dm_atomic_commit_tail() will never acquire a reference to the new stream either, which manifests as a use-after-free when the stream gets disabled later on: BUG: KASAN: use-after-free in dc_stream_release+0x25/0x90 [amdgpu] Write of size 4 at addr ffff88813d836524 by task kworker/9:9/29977 Workqueue: events drm_mode_rmfb_work_fn Call Trace: <TASK> dump_stack_lvl+0x6e/0xa0 print_address_description.constprop.0+0x88/0x320 ? dc_stream_release+0x25/0x90 [amdgpu] print_report+0xfc/0x1ff ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x225/0x4e0 ? dc_stream_release+0x25/0x90 [amdgpu] kasan_report+0xe1/0x180 ? dc_stream_release+0x25/0x90 [amdgpu] kasan_check_range+0x125/0x200 dc_stream_release+0x25/0x90 [amdgpu] dc_state_destruct+0x14d/0x5c0 [amdgpu] dc_state_release.part.0+0x4e/0x130 [amdgpu] dm_atomic_destroy_state+0x3f/0x70 [amdgpu] drm_atomic_state_default_clear+0x8ee/0xf30 ? drm_mode_object_put.part.0+0xb1/0x130 __drm_atomic_state_free+0x15c/0x2d0 atomic_remove_fb+0x67e/0x980 Since there is no reliable way of figuring out whether a CRTC has unrelated mode changes pending at the time of DSC validation, remember the value of the mode_changed flag from before the point where a CRTC was marked as potentially affected by a change in DSC configuration. Reset the mode_changed flag to this earlier value instead in pre_validate_dsc(). (cherry picked from commit cc7c7121ae082b7b82891baa7280f1ff2608f22b)

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

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

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

References

Recent Use After Free vulnerabilities

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