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CVE Record

CVE-2026-43208: net: do not pass flow_id to set_rps_cpu()

In the Linux kernel, the following vulnerability has been resolved: net: do not pass flow_id to set_rps_cpu() Blamed commit made the assumption that the RPS table for each receive queue would have the same size, and that it would not change. Compute flow_id in set_rps_cpu(), do not assume we can use the value computed by get_rps_cpu(). Otherwise we risk out-of-bound access and/or crashes.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A Linux networking flaw can access memory outside an expected table when Receive Packet Steering data changes or queue tables differ in size. The supplied record warns of crashes and out-of-bounds access. Its CVSS rating is critical, but the bundle does not establish practical compromise, affected configurations, or exploitation in the wild.

Executive priority

Prioritize verification and vendor-supported updates because the supplied severity is critical and the flaw can crash kernels. Escalate exposed, availability-sensitive Linux infrastructure first. Do not assume remote compromise is proven: affected-version boundaries and real-world exploitability remain insufficiently documented in the supplied evidence.

Technical view

A flow identifier calculated by get_rps_cpu() was passed to set_rps_cpu() under an unsafe assumption that receive-queue RPS tables share a stable size. Recomputing the identifier inside set_rps_cpu() prevents an out-of-bounds access when table sizes differ or change.

Likely exposure

Potential exposure is limited to Linux systems running affected kernel builds where the relevant networking and RPS path is exercised. The supplied version list includes 6.18, 6.18.16, 6.19.6, 7.0, and an ambiguous "0" entry, but provides no CPEs or clear version ranges. Confirm status through kernel or distribution guidance.

Exploitation context

The supplied CVSS vector describes network reachability, low complexity, no privileges, and no user interaction. However, the bundle provides no exploit demonstration, attack prerequisites, or evidence of active exploitation, and the CVE is not listed as KEV. Treat the CVSS claims cautiously until vendor analysis clarifies practical impact.

Researcher notes

The evidence supports the unsafe cross-function reuse of an RPS flow identifier and the recomputation fix. It does not supply a CWE, proof of concept, affected configuration details, or exploitation evidence. The affected-version data is ambiguous, including duplicate commit identifiers and a "0" version, so branch-specific fix mapping should be verified against the cited commits.

Mitigation direction

  • Inventory running Linux kernel builds and compare them with distribution advisories and the CVE record.
  • Apply a vendor-supported kernel update containing the applicable cited stable fix after compatibility testing.
  • If patching is delayed, check vendor guidance for RPS mitigations; the supplied sources name none.
  • Prioritize network-facing or high-throughput systems where Receive Packet Steering is enabled.

Validation and detection

  • Confirm each running kernel build contains the applicable stable fix or a vendor backport.
  • Determine whether Receive Packet Steering is enabled on affected network receive queues.
  • Review kernel and monitoring records for unexplained networking crashes or memory-access faults.
  • After updating, exercise representative network traffic and verify system stability.
Prepared
Confidence
medium
Sources
5

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-2026-43208 mapping review

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/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
4Source 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
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2026-43208Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/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
LinuxLinux48aa30443e52c9666d5cd5e67532e475f212337e, 48aa30443e52c9666d5cd5e67532e475f212337e, 48aa30443e52c9666d5cd5e67532e475f212337eunaffected
LinuxLinux6.18, 0, 6.18.16, 6.19.6, 7.0affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.