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CVE Record

CVE-2025-38552: mptcp: plug races between subflow fail and subflow creation

In the Linux kernel, the following vulnerability has been resolved: mptcp: plug races between subflow fail and subflow creation We have races similar to the one addressed by the previous patch between subflow failing and additional subflow creation. They are just harder to trigger. The solution is similar. Use a separate flag to track the condition 'socket state prevent any additional subflow creation' protected by the fallback lock. The socket fallback makes such flag true, and also receiving or sending an MP_FAIL option. The field 'allow_infinite_fallback' is now always touched under the relevant lock, we can drop the ONCE annotation on write.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-38552 is a Linux kernel flaw in MPTCP connection handling. A race can occur when one subflow fails while another is being created. The public record does not provide a CVSS score, confirmed impact, or active exploitation evidence, so business urgency depends on where affected kernels and MPTCP are used.

Executive priority

Treat this as a kernel maintenance and exposure-mapping item, not an emergency based on current evidence. Prioritize assets using MPTCP, externally reachable systems, and products covered by Debian or Siemens advisories. Reassess if a vendor assigns severity or exploitation evidence emerges.

Technical view

The fix adds locked state tracking to prevent additional MPTCP subflow creation after socket fallback or MP_FAIL handling. The source describes races between subflow failure and additional subflow creation, similar to a previous kernel patch. Version-range semantics are incomplete in the bundle, but Linux kernel stable commits are referenced.

Likely exposure

Exposure is most plausible on Linux systems using kernels in affected stable lines with MPTCP enabled or available. Internet-facing, appliance, embedded, and industrial systems should be checked first. The bundle does not prove default exploitability or identify affected distributions beyond referenced Debian and Siemens advisories.

Exploitation context

No CISA KEV entry is indicated, and the provided sources do not cite active exploitation or public weaponization. The kernel description says the races are harder to trigger. Preconditions, attacker position, privileges, and security impact are not specified in the supplied record.

Researcher notes

The source bundle lacks CVSS, CWE, explicit impact, and exploit prerequisites. Avoid over-classifying risk. Focus analysis on MPTCP state transitions, fallback locking, MP_FAIL handling, and whether deployed kernels contain one of the referenced stable fixes.

Mitigation direction

  • Apply Linux kernel updates containing the referenced stable MPTCP race fixes.
  • Use vendor packages rather than manually cherry-picking kernel patches where possible.
  • Review Debian LTS guidance if Debian systems are in scope.
  • Review Siemens SSA-032379 for affected Siemens products or firmware dependencies.
  • If no vendor fix is available, monitor vendor guidance and assess MPTCP exposure.

Validation and detection

  • Inventory Linux kernel versions across servers, appliances, containers hosts, and embedded systems.
  • Determine whether MPTCP is enabled, exposed, or required on each affected asset.
  • Map assets against vendor advisories and the referenced kernel stable commits.
  • Confirm patched kernels are installed and active after reboot.
  • Record exceptions where vendor guidance is unavailable or versions cannot be mapped.
Prepared
Confidence
medium
Sources
9

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-2025-38552 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
2ADP providers
8Source links

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

CVECVE Program Container
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux478d770008b03ed9d74bdc8add2315b7fd124ecc, 478d770008b03ed9d74bdc8add2315b7fd124ecc, 478d770008b03ed9d74bdc8add2315b7fd124ecc, 478d770008b03ed9d74bdc8add2315b7fd124ecc, 478d770008b03ed9d74bdc8add2315b7fd124eccunaffected
LinuxLinux5.15, 0, 6.1.149, 6.6.101, 6.12.40, 6.15.8, 6.16affected
Weakness

CWE details

No CWE listed

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