9.4

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

Modified
AliasesUBUNTU-CVE-2025-38552DEBIAN-CVE-2025-38552
Published 16-08-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-38552 is a critical (CVSS 9.4) vulnerability in debian debian_linux. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.4 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.4/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.33%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 39 · Related 37
DLA-4328-1DSA-6009-1OPENSUSE-SU-2025:20081-1SUSE-SU-2025:21040-1SUSE-SU-2025:21052-1SUSE-SU-2025:21056-1

Timeline

  1. 16-08-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.32% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu136 products
  • linuxAll versions (No fix recorded) | < 6.8.0-100.100
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1046.49
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.153-1 | < 6.12.41-1 | < 6.16.3-1
  • debian_linuxEOL11.0
Linux2 products
  • linux≥ 478d770008b03ed9d74bdc8add2315b7fd124ecc, < c476d627584b7589a134a8b48dd5c6639e4401c5 | ≥ 478d770008b03ed9d74bdc8add2315b7fd124ecc, < 7c96d519ee15a130842a6513530b4d20acd2bfcd | ≥ 478d770008b03ed9d74bdc8add2315b7fd124ecc, < f81b6fbe13c7fc413b5158cdffc6a59391a2a8db | ≥ 478d770008b03ed9d74bdc8add2315b7fd124ecc, < 659da22dee5ff316ba63bdaeeac7b58b5442f6c2 | ≥ 478d770008b03ed9d74bdc8add2315b7fd124ecc, < def5b7b2643ebba696fc60ddf675dca13f073486 | 5.15
  • linux_kernel≥ 5.15, < 6.1.149 | ≥ 6.2, < 6.6.101 | ≥ 6.7, < 6.12.40 | ≥ 6.13, < 6.15.8 | 6.16:rc1 | 6.16:rc2 | 6.16:rc3 | 6.16:rc4 | 6.16:rc5 | 6.16:rc6

3 vendors · 140 products

References

34 links
Show all 34 references