Security readout for executives and security teams
Plain-English summary
A race condition in Linux’s Open vSwitch port removal can free network-device memory while teardown still uses it. The supplied evidence shows a kernel protection fault and likely system crash, especially under real-time preemption. It requires local interaction; exact privileges and broader compromise potential are not established by the bundle.
Executive priority
Remediate promptly through the normal high-severity patch cycle, accelerating PREEMPT_RT hosts using Open vSwitch. Immediate emergency action is not supported by the supplied exploitation evidence, but kernel crashes on network infrastructure can create material availability risk.
Technical view
ovs_netdev_detach_dev clears IFF_OVS_DATAPATH before unregistration finishes. If preempted, netdev_destroy can observe the cleared flag, proceed through call_rcu, and release the device while teardown remains active. Later processing accesses invalid device state, causing a general protection fault. The stable patches prevent release before teardown completes.
Likely exposure
Exposure concerns affected Linux kernels using in-kernel Open vSwitch and performing port or network-device teardown. PREEMPT_RT increases plausibility because the documented failure involves preemption after flag clearing. The supplied flattened version data is insufficient for dependable distribution-level mapping; verify vendor backports or applicable stable patch presence.
Exploitation context
The bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. CVSS identifies a local, low-privilege vector without user interaction. However, exact operational privileges are unclear, and the supplied evidence demonstrates a kernel crash rather than proven confidentiality or integrity compromise.
Researcher notes
The reported fault occurred on a 6.12-based PREEMPT_RT kernel. CVSS is 7.8 with local access, low complexity, low privileges, and high confidentiality, integrity, and availability impacts. The bundle demonstrates premature device release and a crash, but does not establish reliable code execution, exact privilege requirements, or complete distribution-specific affected ranges.
Mitigation direction
- Install a vendor-supported kernel containing the applicable Linux stable fix.
- Prioritize PREEMPT_RT systems actively using Open vSwitch.
- Restrict untrusted local access and unnecessary authority to manage OVS ports until patched.
- Review distribution or appliance-vendor guidance for backport status and reboot requirements.
Validation and detection
- Inventory running kernels, PREEMPT_RT usage, and systems actively using in-kernel Open vSwitch.
- Confirm the installed vendor kernel contains an applicable stable patch or documented backport.
- After updating and rebooting, verify the running kernel matches the remediated package.
- Review kernel logs for faults involving ovs_netdev_detach_dev, dp_device_event, or dev_set_promiscuity.
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
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CVE-2026-31508 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
- 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.
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:H/I:H/A:H1.85.9LinuxVulnerability 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
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/df3c95be76103604e752131d9495a24814915eceCVE reference, Linux
- https://git.kernel.org/stable/c/33609454be4f582e686a4bf13d4482a5ca0f6c4bCVE reference, Linux
- https://git.kernel.org/stable/c/5fdeaf591a0942772c2d18ff3563697a49ad01c6CVE reference, Linux
- https://git.kernel.org/stable/c/4c3e25a7b711a402fcbbbcfbbdf2868ece1ae7c8CVE reference, Linux
- https://git.kernel.org/stable/c/43579baa17270aa51f93eb09b6e4af6e047b7f6eCVE reference, Linux
- https://git.kernel.org/stable/c/95265232b49765a4d00f4d028c100bb7185600f4CVE reference, Linux
- https://git.kernel.org/stable/c/755a6300afbd743cda4b102f24f343380ec0e0ffCVE reference, Linux
- https://git.kernel.org/stable/c/7c770dadfda5cbbde6aa3c4363ed513f1d212bf8CVE reference, Linux
- https://cert-portal.siemens.com/productcert/html/ssa-082556.htmlCVE reference, siemens-SADP
- https://cert-portal.siemens.com/productcert/html/ssa-019113.htmlCVE reference, siemens-SADP
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.