CVE-2025-38211VulnerabilityPublished 2 Sep 2025Updated 22 Oct 2026

Red Hat Security Advisory: kernel security update

Affects Red Hat kernelSource GCVE Database

Not known to be exploited · fixed in Red Hat package updates : update Red Hat kernel when convenient.

Data as of 26 Oct 2026, 08:30 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.15.0-1096.105~20.04.1, 5.15.0-1092.101~20.04.1, 5.15.0-1092.99~20.04.1 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Red Hat Product Security Red Hat	Affected <5.15.0-1092.99~20.04.1 <5.15.0-1096.105~20.04.1 <5.15.0-1092.101~20.04.1 <5.15.0-156.166~20.04.1 <5.15.0-1086.89~20.04.1 <5.15.0-1092.99~20.04.1 <5.15.0-1096.105~20.04.1 <5.15.0-1092.101~20.04.1 <5.15.0-156.166~20.04.1 <5.15.0-1086.89~20.04.1	Fixed in 5.15.0-1092.99~20.04.1 5.15.0-1096.105~20.04.1 5.15.0-1092.101~20.04.1 5.15.0-156.166~20.04.1 5.15.0-1086.89~20.04.1

AI-suggested

Red Hat has released an official security update for Red Hat Enterprise Linux 8 that fixes this vulnerability. Applying the kernel update and rebooting the system is required to remediate the issue. No additional mitigation steps are necessary beyond applying the vendor-provided patch.

Description

A use-after-free vulnerability in the Linux kernel's RDMA iwcm component was fixed by Red Hat. The flaw involves work objects associated with cm_id_private that could be accessed after being freed during cm_id destruction, leading to kernel bugs. This issue was reproducible with specific test cases involving the rdma transport and siw driver. Red Hat has released a security update for Red Hat Enterprise Linux 8 to address this vulnerability. The update requires a system reboot to take effect.

Impact

This vulnerability can cause kernel crashes or instability due to use-after-free conditions in the RDMA iwcm subsystem. While no known exploits in the wild have been reported, the flaw could potentially be triggered by workloads using RDMA connections, leading to denial of service or system instability.

Summary

The vulnerability (CVE-2025-38211) is a use-after-free bug in the Linux kernel's RDMA iwcm (iWARP Connection Manager) subsystem. It arises because work objects allocated per cm_id_private during cm_id creation could be freed prematurely if the last reference to the cm_id is decremented within event handler work, causing the work object to be removed while still in use. This leads to a kernel slab-use-after-free detected by KASAN. The issue was addressed by ensuring the last reference decrement happens in the cm_id destruction context rather than in event handler works, preventing use-after-free conditions. The bug was reproducible with the blktests nvme/061 test case for the rdma transport and siw driver. Red Hat has issued a kernel update for Red Hat Enterprise Linux 8 that fixes this flaw.

CWE-416Use After Free (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #7
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Architecture and Design · Language Selection
Choose a language that provides automatic memory management.
Implementation · Attack Surface Reduction
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-170Improper Null Termination (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.
Requirements
Use a language that is not susceptible to these issues. However, be careful of null byte interaction errors (CWE-626) with lower-level constructs that may be written in a language that is susceptible.
Implementation
Ensure that all string functions used are understood fully as to how they append null characters. Also, be wary of off-by-one errors when appending nulls to the end of strings.
Implementation
If performance constraints permit, special code can be added that validates null-termination of string buffers, this is a rather naive and error-prone solution.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 22 Oct 2026, 17:52 UTC

WeaknessesCWE-416, CWE-170

Technical details

References

Community reviews

Related threats