CyberSecBulletin
CVE-2026-64524NVD status: Analyzed

Linux: Heap-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2026-64524 is a high-severity heap-based buffer overflow vulnerability in Linux, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions 96f7de3172d4aa878b7f87173b2b3507c350fcd6, bc573752f3dac0d1ab8df7078c1851bc76717653, 1fb565b77b8f44afabb02de6310065f109d89e94 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 96f7de3172d4aa878b7f87173b2b3507c350fcd6 or bc573752f3dac0d1ab8df7078c1851bc76717653 or 1fb565b77b8f44afabb02de6310065f109d89e94 or a321c908f2eeea01539668eb270d074d9b88e490, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.210 or 6.1.176 or 6.6.143 or 6.12.93, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, 96f7de3172d4aa878b7f87173b2b3507c350fcd6; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, bc573752f3dac0d1ab8df7078c1851bc76717653; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, 1fb565b77b8f44afabb02de6310065f109d89e94; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, a321c908f2eeea01539668eb270d074d9b88e490; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, 9c698b2c43c2667c34f5336bf46ad5786216ac2a; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, 8a114b25b5521eae451b13bce98ae978624962e5; 76c56a5affeba1e163b66b9d8cc192e6154466f0 up to, but not including, 13d33b9ef67066c77c84273fac5a1d3fde3533d1; 5.1496f7de3172d4aa878b7f87173b2b3507c350fcd6, bc573752f3dac0d1ab8df7078c1851bc76717653, 1fb565b77b8f44afabb02de6310065f109d89e94, a321c908f2eeea01539668eb270d074d9b88e490, 9c698b2c43c2667c34f5336bf46ad5786216ac2a, 8a114b25b5521eae451b13bce98ae978624962e5
LinuxLinux Kernel5.14 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, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.15.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12

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
NoneNo account or login is needed.
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:N/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: drm/hyperv: validate resolution_count and fix WIN8 fallback A SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past the supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the parse loop. Bound resolution_count against the array size, folded into the existing zero-check. When the WIN10 resolution probe fails, the caller in hyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated, which sets mode_config.max_width / max_height to 0 and makes drm_internal_framebuffer_create() reject every userspace framebuffer with -EINVAL. The pre-WIN10 branch had the same gap for preferred_width / preferred_height. Use a single post-probe fallback guarded by screen_width_max == 0 so both paths converge on the WIN8 defaults.

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

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Heap-based Buffer Overflow vulnerabilities (CWE-122)

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 Heap-based Buffer Overflow vulnerabilities

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