Security readout for executives and security teams
Plain-English summary
CVE-2025-21911 is a Linux kernel availability issue in the Imagination/PowerVR DRM graphics driver. A local user can trigger a locking deadlock during graphics fence release handling, potentially hanging affected graphics-related workloads or the system path involved. It is not described as exposing data or enabling code execution.
Executive priority
Treat as a targeted availability risk, not a broad remote compromise issue. Patch through normal kernel maintenance, faster for devices where graphics availability affects operations or customer service.
Technical view
The flaw is a CWE-667 improper locking issue in drm/imagination. Fence release processing ran inside the release function and could recursively acquire reservation locks, causing deadlock. The kernel fix moves scheduler queue fence release processing onto a workqueue.
Likely exposure
Exposure is most likely on Linux systems running affected kernels with the drm/imagination PowerVR graphics driver present or enabled. The CVE data identifies Linux kernel versions around 6.8 and later stable lines, but exact distribution exposure depends on backported fixes.
Exploitation context
The CVSS vector is local, low complexity, low privileges, and no user interaction, with high availability impact only. The provided sources do not report active exploitation, and CISA KEV status is false.
Researcher notes
Evidence supports a local denial-of-service class issue caused by lock recursion during fence release. Public data names stable kernel commits but does not provide exploit details or confirm exploitation in the wild.
Mitigation direction
- Apply vendor Linux kernel updates containing the referenced stable fixes.
- Prioritize systems using Imagination or PowerVR graphics hardware or drivers.
- Confirm distribution kernels include the backported fix before marking remediated.
- If patching is delayed, follow vendor guidance for reducing driver exposure.
Validation and detection
- Inventory kernel versions and whether drm/imagination or powervr modules are present.
- Check vendor changelogs for the referenced stable commit backports.
- Review logs for recursive locking or deadlock warnings involving powervr or reservation locks.
- Run normal graphics workload regression tests after kernel update.
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-667: 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-2025-21911 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/d993ae7360923efd6ade43a32043459a121c28c1CVE reference, Linux
- https://git.kernel.org/stable/c/9bd8b8d34cf4efba18766d64f817c819ed1bbde7CVE reference, Linux
- https://git.kernel.org/stable/c/df1a1ed5e1bdd9cc13148e0e5549f5ebcf76cf13CVE 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.