CVE-2026-39255

Heap corruption via racy unbounded wide-string copy

Published Aug 17, 2026 · Updated Aug 18, 2026

Heap buffer overflow in SteelSeries GG 107.0.0 for macOS allows physically proximate attackers to corrupt process memory via HID metadata. The libSSEdevice.dylib dup_wcs helper sizes an allocation using wcslen, then wcscpy copies the mutable source without a bound; growth between the calls overruns the heap. Reachability requires attacker-influenced or emulated HID data and a race that changes the source between measurement and copying; controlled tests proved crashes and heap corruption, not code execution.

CVSS severity9.8
Critical
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in SteelSeries GG 107.0.0 for macOS allows physically proximate attackers to corrupt process memory via HID metadata. The libSSEdevice.dylib dup_wcs helper sizes an allocation using wcslen, then wcscpy copies the mutable source without a bound; growth between the calls overruns the heap. Reachability requires attacker-influenced or emulated HID data and a race that changes the source between measurement and copying; controlled tests proved crashes and heap corruption, not code execution.

The record

CVE
CVE-2026-39255
Published
Aug 17, 2026
Updated
Aug 18, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1200Hardware Additions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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