Security readout for executives and security teams
Plain-English summary
A Linux kernel cleanup error in the io_uring futex-wait path can leave invalid request state referencing freed data. A low-privileged local user could potentially turn this into serious confidentiality, integrity, and availability impact. The supplied record rates it high severity at CVSS 8.8.
Executive priority
Treat as a high-priority kernel update, especially on shared systems or hosts executing untrusted workloads. It is not supported as an internet-remote or actively exploited issue by the supplied evidence, so prioritize according to local-code execution exposure and vendor-confirmed affected status.
Technical view
io_futex_wait() assigned allocated io_futex_data to async_data without setting REQ_F_ASYNC_DATA. Its failure path then freed the data without clearing async_data. The fix keeps the pointer and validity flag synchronized during setup and error cleanup, addressing expired-resource use tracked as CWE-672.
Likely exposure
Exposure is limited to Linux systems running an affected kernel and reachable by a low-privileged local user or workload. The supplied version data is ambiguous, so kernel or distribution advisories should determine whether a specific build contains one of the referenced fixes.
Exploitation context
The CVSS vector indicates local access, low privileges, low complexity, and no user interaction. The source bundle does not establish active exploitation, and the CVE is not listed as KEV. ZDI is credited with reporting the issue, but this evidence alone does not indicate attacks in the wild.
Researcher notes
The core invariant is that async_data and REQ_F_ASYNC_DATA must be set and cleared together. Failure cleanup previously freed io_futex_data while retaining stale request state. The supplied affected-version representation is insufficient for precise branch boundaries; use the upstream commits and distribution backport records for confirmation.
Mitigation direction
- Install a vendor-supported kernel containing the applicable referenced stable fix.
- Check distribution advisories for backports because package versions may not match upstream kernel versions.
- Prioritize multi-user systems and hosts running untrusted or tenant-controlled workloads.
- Restrict untrusted local access where patching cannot be completed promptly.
Validation and detection
- Inventory running kernel versions across Linux hosts and compare them with vendor advisories.
- Confirm whether vendor builds include an applicable referenced kernel commit or documented backport.
- Verify upgraded hosts are running the corrected kernel after required restarts.
- Review exposure to low-privileged local users and untrusted workloads until remediation is complete.
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-672: 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-2025-39698 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
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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:C/C:H/I:H/A:H26CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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/d9f93172820a53ab42c4b0e5e65291f4f9d00ad2CVE reference, Linux
- https://git.kernel.org/stable/c/d34c04152df517c59979b4bf2a47f491e06d3256CVE reference, Linux
- https://git.kernel.org/stable/c/508c1314b342b78591f51c4b5dadee31a88335dfCVE reference, Linux
- https://www.zerodayinitiative.com/advisories/ZDI-25-915/CVE 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.
Operation on a Resource after Expiration or Release
Operation on a Resource after Expiration or Release represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.