Security readout for executives and security teams
Plain-English summary
A memory-safety error in the Linux Intel Touch Host Controller HID driver can write beyond allocated memory and crash the kernel. The supplied CVSS rating is 7.8 (high). Successful abuse requires local access with low privileges; the evidence does not establish remote reachability or real-world exploitation.
Executive priority
Treat confirmed affected systems as a high-priority patching item, especially multi-user endpoints. This is not evidenced as an internet-scale emergency because access is local and active exploitation is unconfirmed. Prompt remediation remains appropriate because kernel memory corruption can cause system compromise or denial of service.
Technical view
Incorrect pointer arithmetic in thc_i2c_subip_regs_save passed the secondary array pointer incorrectly during a regmap bulk read, producing a four-byte slab out-of-bounds write. The correction directly indexes i2c_subip_regs. The CVSS vector indicates local, low-complexity, low-privilege exploitation without user interaction and potentially high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to Linux systems containing the affected Intel THC HID I2C driver path and an affected kernel build. The supplied affected-version data names 6.14, 6.16.5, and 6.17, but also contains an ambiguous "0" entry; confirm exact ranges against distribution and kernel-maintainer advisories.
Exploitation context
The CVSS vector describes a local attack requiring low privileges. The documented failure occurred in a kernel worker and caused an out-of-bounds write and kernel crash. The supplied record is not in KEV and provides no evidence of active exploitation, public exploit availability, or reliable privilege escalation.
Researcher notes
KASAN recorded a four-byte write immediately beyond a 192-byte allocation in _regmap_bulk_read, reached through pio_complete and thc_i2c_subip_regs_save. The stated fix uses &dev->i2c_subip_regs[i]. The supplied bundle does not establish exploitability beyond the observed crash, affected hardware breadth, or complete fixed-version boundaries.
Mitigation direction
- Apply a vendor or distribution kernel update containing the referenced stable fix.
- Confirm the installed update replaces the faulty pointer use with direct array indexing.
- If updating is delayed, consult vendor guidance for supported exposure-reduction measures.
- Prioritize affected shared workstations or systems where untrusted users can obtain local access.
Validation and detection
- Inventory kernel versions on systems using Intel THC HID hardware or drivers.
- Confirm whether the intel_thc I2C driver path is present and active.
- Map installed builds to distribution advisories and the referenced stable commits.
- After updating, verify the running kernel includes the fix and review logs for related crashes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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Open ATT&CK lookupCVE-2025-39818 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/78d4cf0466c79452e47aa6f720afbde63e709cccCVE reference, Linux
- https://git.kernel.org/stable/c/a7fc15ed629be89e51e09b743277c53e0a0168f5CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.