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CVE Record

CVE-2026-31532: can: raw: fix ro->uniq use-after-free in raw_rcv()

In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. [mkl: applied manually]

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux kernel race in raw CAN socket cleanup can access memory after it has been freed. A local user with limited privileges could potentially cause serious loss of confidentiality, integrity, or availability. Systems using CAN networking deserve particular attention.

Executive priority

Treat as a high-priority kernel update for CAN-enabled or multi-user Linux systems. It is not evidenced as an internet-remote or actively exploited threat, so prioritize by local access, CAN usage, workload trust, and operational criticality.

Technical view

raw_release() freed per-CPU ro->uniq storage while deferred RCU receiver deletion could leave raw_rcv() accessing it. The fix delays that free until the socket destructor runs, after relevant callbacks and socket references have drained. CVSS 3.1 is 7.8: local, low complexity, low privileges, no user interaction.

Likely exposure

Exposure is limited to Linux systems running an affected kernel and exercising raw CAN sockets. The supplied version data is not sufficiently clear for reliable package-level conclusions; confirm each distribution kernel against vendor guidance and the referenced stable commits.

Exploitation context

The supplied record marks this CVE as absent from KEV and provides no evidence of active exploitation or a public exploit. Exploitation requires local, low-privileged access according to the CVSS vector. Practical exploitability is not established by these sources.

Researcher notes

The vulnerable lifetime transition involves raw CAN receiver unregistration, deferred RCU deletion, and premature free_percpu(ro->uniq). The patch moves release into a raw-specific socket destructor. The supplied affected-version representation appears ambiguous, so commit ancestry and distribution backport analysis are more dependable than version-string matching alone.

Mitigation direction

  • Install a vendor-supported kernel containing the applicable referenced stable fix.
  • Reboot into the updated kernel after installation.
  • Prioritize CAN-enabled systems accessible to local users or untrusted workloads.
  • Check distribution security guidance where version or backport status is unclear.

Validation and detection

  • Inventory running kernel versions on systems supporting CAN networking.
  • Compare distribution packages and backports with CVE-2026-31532 vendor guidance.
  • Confirm the running kernel contains the applicable stable commit after reboot.
  • Verify update management reports no remaining vulnerable kernel package.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

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CVE-2026-31532 mapping review

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Vulnerability profileCVE Program record
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

Official CVE source material

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.

1CVSS vectors
3Timeline events
0ADP providers
10Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-31532Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4a, 514ac99c64b22d83b52dfee3b8becaa69a92bc4aunaffected
LinuxLinux4.1, 0, 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1affected
Weakness

CWE details

No CWE listed

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