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CVE Record

CVE-2024-26708: mptcp: really cope with fastopen race

In the Linux kernel, the following vulnerability has been resolved: mptcp: really cope with fastopen race Fastopen and PM-trigger subflow shutdown can race, as reported by syzkaller. In my first attempt to close such race, I missed the fact that the subflow status can change again before the subflow_state_change callback is invoked. Address the issue additionally copying with all the states directly reachable from TCP_FIN_WAIT1.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2024-26708 is a Linux kernel availability issue in Multipath TCP handling. A race between TCP Fast Open and subflow shutdown can trigger incorrect state handling. The CVSS vector indicates local, low-complexity exploitation by a low-privileged user, with no confidentiality or integrity impact but potential high availability impact.

Executive priority

Treat as a moderate kernel maintenance priority. It is not currently evidenced as actively exploited, but availability impact can matter on shared or production Linux infrastructure. Fold remediation into kernel update cycles, accelerating for multi-user and internet-facing operational platforms.

Technical view

The flaw is in Linux kernel MPTCP state handling. Fast Open and path-manager-triggered subflow shutdown can race, and subflow state may change before the subflow_state_change callback runs. The fix accounts for states directly reachable from TCP_FIN_WAIT1. Public sources identify stable kernel commits as the resolution.

Likely exposure

Exposure is most relevant to Linux systems running affected kernel versions with MPTCP code present, especially multi-user systems where untrusted local users exist. The CVE record lists Linux kernel version entries including 6.2, 6.6.18, 6.7.6, and 6.8, but distro package status requires vendor confirmation.

Exploitation context

The CVE is not listed as CISA KEV in the supplied bundle. The report mentions syzkaller, which indicates automated kernel testing found the race. No cited source claims real-world exploitation, public exploit availability, or remote unauthenticated attackability.

Researcher notes

The source evidence is narrow: CVE metadata and three Linux stable commits. The root issue is a race in MPTCP Fast Open and subflow shutdown state transitions. Validate exact affected ranges through downstream distro advisories because vendor backports may differ from upstream version labels.

Mitigation direction

  • Update Linux kernels to vendor builds containing the referenced stable fixes.
  • Check distribution advisories for CVE-2024-26708 package status.
  • Prioritize systems with untrusted local users or exposed multi-tenant workloads.
  • Avoid direct wrangling of kernel patches unless vendor guidance requires it.

Validation and detection

  • Inventory Linux kernel versions across servers, containers hosts, and appliances.
  • Confirm distro changelogs mention CVE-2024-26708 or the referenced commits.
  • Check whether MPTCP is enabled or used on in-scope systems.
  • Review kernel crash logs for unexplained MPTCP-related availability events.
Prepared
Confidence
high
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.

ATT&CK lookup starting points

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CVE-2024-26708 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
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

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
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

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
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2024-26708Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1e777f39b4d75e599a3aac8e0f67d739474f198c, 1e777f39b4d75e599a3aac8e0f67d739474f198c, 1e777f39b4d75e599a3aac8e0f67d739474f198cunaffected
LinuxLinux6.2, 0, 6.6.18, 6.7.6, 6.8affected
Weakness

CWE details

No CWE listed

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