High

CVE-2025-40253 — s390/ctcm: Fix double-kfree

In the Linux kernel, the following vulnerability has been resolved: s390/ctcm: Fix double-kfree The function 'mpc_rcvd_sweep_req(mpcginfo)' is called conditionally from function 'ctcmpc_unpack_skb'. It frees passed mpcginfo. After that a call to function 'kfree' in function 'ctcmpc_unpack_skb' frees it again. Remove 'kfree' call in function 'mpc_rcvd_sweep_req(mpcginfo)'. Bug detected by the clang static analyzer.

Published Dec 4, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+3
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.3%

ahead of 21% of scored CVEs · Oct 14, 2026

Affects

Linux

CVSS base

8.8

High · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	version 4c9ba0fed125deba8416b995b0c274b0804c0c24version 5.18≥ 5.17.9 and < 5.18≥ 4.19.244 and < 4.20≥ 4.14.280 and < 4.15≥ 4.9.315 and < 4.10≥ 5.15.41 and < 5.15.197≥ 5.10.117 and < 5.10.247 and 12 more ≥ 5.4.195 and < 5.4.302version ea0053af5dab4d63a9c44563973fb2f3bfd9eb2b≥ 467ddbbe7e749d558f13e640f50f546149c930b3 and < 06f1dd1de0d33dbfbd2e1fc9fc57d8895f730de2version d886b4292a1c5b4facdb2dfdc31f0fecc71df898version 36933de59f67029e5739a98393891f9b94f27e0f≥ 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a and < da02a1824884d6c84c5e5b5ac373b0c9e3288ec2≥ 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a and < 7ff76f8dc6b550f8d16487bf3cebc278be720b5c≥ 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a and < b9dbfb1b5699f9f1e4991f96741bdf9047147589≥ 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a and < 3b177b2ded563df16f6d5920671ffcfe5915d472≥ 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a and < 43096dab8cc60fc39133205fd149a54d3acebea8≥ 2bd57101c3ecf3f8c0da1d26c2b6ad511adc6d50 and < 7616e2eee679746d526c7f5befd4eedb995935b5≥ 4d3c6d741816539b57fa1110c3f765a8c176d7b4 and < 6bf8ccaabce8cebb6cb1f255c93d0acdfe95c17a	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Adjacent

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.8	CVSS 3.1	High	2.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.30%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 8.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Deferred
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
2025
CVE published
Dec 4, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

git.kernel.org/stable/c/b9dbfb1b5699f9f1e4991f96741bdf9047147589
NIST National Vulnerability Database
git.kernel.org/stable/c/7ff76f8dc6b550f8d16487bf3cebc278be720b5c
NIST National Vulnerability Database
git.kernel.org/stable/c/3b177b2ded563df16f6d5920671ffcfe5915d472
NIST National Vulnerability Database
git.kernel.org/stable/c/6bf8ccaabce8cebb6cb1f255c93d0acdfe95c17a
NIST National Vulnerability Database
git.kernel.org/stable/c/06f1dd1de0d33dbfbd2e1fc9fc57d8895f730de2
NIST National Vulnerability Database
git.kernel.org/stable/c/7616e2eee679746d526c7f5befd4eedb995935b5
NIST National Vulnerability Database
git.kernel.org/stable/c/43096dab8cc60fc39133205fd149a54d3acebea8
NIST National Vulnerability Database
git.kernel.org/stable/c/da02a1824884d6c84c5e5b5ac373b0c9e3288ec2
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-40253 is "s390/ctcm: Fix double-kfree", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 0.30% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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