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CVE Record

CVE-2025-39760: usb: core: config: Prevent OOB read in SS endpoint companion parsing

In the Linux kernel, the following vulnerability has been resolved: usb: core: config: Prevent OOB read in SS endpoint companion parsing usb_parse_ss_endpoint_companion() checks descriptor type before length, enabling a potentially odd read outside of the buffer size. Fix this up by checking the size first before looking at any of the fields in the descriptor.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2025-39760 is a Linux kernel USB parsing flaw. The kernel could read past the provided buffer while handling a SuperSpeed endpoint companion descriptor. The public record does not provide CVSS, confirmed impact, or active exploitation evidence, so urgency depends on USB exposure and kernel update posture.

Executive priority

Treat as a kernel maintenance priority, not an emergency based on current evidence. Accelerate remediation for systems exposed to untrusted USB devices or appliances covered by vendor advisories.

Technical view

In usb_parse_ss_endpoint_companion(), the Linux kernel checked descriptor type before validating descriptor length. That order could allow an out-of-bounds read when parsing malformed USB configuration data. Stable kernel commits change the logic to check size before accessing descriptor fields.

Likely exposure

Systems running affected Linux kernel versions are potentially exposed when the kernel parses USB device configuration descriptors. Risk is higher where untrusted physical USB devices, pass-through USB, lab equipment, kiosks, or industrial/embedded Linux systems are present.

Exploitation context

The bundle does not cite active exploitation, public exploit code, or KEV listing. The plausible attack surface is malformed USB descriptor parsing, but the sources do not establish practical exploitability, privilege impact, or remote reachability.

Researcher notes

Evidence supports an out-of-bounds read caused by field access before length validation. Public data lacks CVSS, CWE, proof of exploitability, or detailed impact. Avoid assuming code execution or active exploitation without additional vendor evidence.

Mitigation direction

  • Update Linux kernels to vendor-supported fixed versions when available.
  • Apply Debian LTS or other distribution kernel advisories where applicable.
  • Restrict untrusted USB device attachment on sensitive systems.
  • Review vendor guidance for embedded or appliance Linux products.
  • Prioritize systems with physical, kiosk, lab, or pass-through USB exposure.

Validation and detection

  • Inventory Linux kernel versions across servers, endpoints, appliances, and embedded systems.
  • Check distribution advisories for backported fixes, not only upstream version numbers.
  • Confirm whether systems allow untrusted USB or USB pass-through.
  • Verify kernel packages include the referenced stable fixes.
  • Track vendor advisories for Siemens or other downstream products.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2025-39760 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
3ADP providers
12Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
siemens-SADPADP container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8, 842f16905dfc6743c1dd80c3d29b49ba3ab7f7c8unaffected
LinuxLinux2.6.35, 0, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.