Security readout for executives and security teams
Plain-English summary
This is a Linux kernel availability bug in the MediaTek DRM display driver. After a display hotplug event, cursor updates can continue and hit a NULL CRTC state, causing a kernel panic. The business impact is local denial of service on affected MediaTek-based Linux systems, not data theft or remote compromise based on the supplied sources.
Executive priority
Treat as a moderate operational stability issue. Prioritize patching for MediaTek-based endpoints, kiosks, appliances, or embedded systems where a local crash causes service disruption. It is not presented as remote code execution or data exposure in the supplied evidence.
Technical view
CVE-2025-39807 is a CWE-476 NULL pointer dereference in drm/mediatek atomic_disable handling. The failing path involves cursor plane updates after hotplug, where old_state->crtc may be NULL. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, availability high, confidentiality and integrity none.
Likely exposure
Exposure appears limited to Linux systems using the MediaTek DRM display stack and affected kernel versions or downstream kernels missing the referenced stable fixes. Headless servers and non-MediaTek display stacks are less likely to be exposed, but vendor kernel backports must be checked.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The CVSS vector requires local access with low privileges. The plausible impact is a local crash or device disruption, especially around display hotplug and cursor update behavior.
Researcher notes
Version metadata in the bundle is incomplete and should be validated against the CVE record and kernel stable commits. The affected area is drm/mediatek cursor and plane update handling after hotplug. Avoid broad Linux-wide risk claims without confirming MediaTek DRM use and patch presence.
Mitigation direction
- Apply vendor kernel updates that include the referenced Linux stable fixes.
- Prioritize MediaTek-based devices with interactive display or hotplug use cases.
- Check downstream kernel vendor advisories before assuming upstream version status.
- If updates are unavailable, reduce exposure of affected interactive display workloads where practical.
Validation and detection
- Inventory Linux devices using MediaTek DRM/display hardware or kernels.
- Compare running kernel versions and vendor patch levels against CVE metadata.
- Confirm whether referenced stable commits are present in downstream kernel trees.
- Review crash logs for NULL pointer panics in mtk_crtc_plane_disable or related DRM paths.
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
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-39807 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
1 official scoreWe 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:N/I:N/A:H1.83.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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/7d5cc22efa44e0fe321ce195c71c3d7da211fbb2CVE reference, Linux
- https://git.kernel.org/stable/c/9a94e9d8b50bcfe89693bc899a54d3866d86e973CVE reference, Linux
- https://git.kernel.org/stable/c/0c6b24d70da21201ed009a2aca740d2dfddc7ab5CVE 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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.