CVE-2025-38527VulnerabilityPublished 6 Oct 2025Updated 30 Jul 2026

Red Hat Security Advisory: kernel security update

Affects Red HatSource GCVE Database

Mentioned vulnerabilities

CVE-2025-39730

Not known to be exploited : upgrade to 8.10 when convenient.

Data as of 25 Oct 2026, 19:02 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 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 8.10

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 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 2026-10-25.

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 redhat/kernel to 8.10.

Affected software

Product	Affected	Fixed in
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =8 <8.10	Fixed in 8.10

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Red Hat has released updated kernel packages that address these vulnerabilities. Users of Red Hat Enterprise Linux 8 should apply the kernel update as described in the Red Hat advisory RHSA-2025:17397. A system reboot is required for the update to take effect. No additional mitigations are specified or required beyond applying the official update.

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: smb: client: fix use-after-free in cifs_oplock_break (CVE-2025-38527) * kernel: NFS: Fix filehandle bounds checking in nfs_fh_to_dentry() (CVE-2025-39730) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Impact

The vulnerabilities affect the Linux kernel, which is the core of the operating system. The use-after-free in the SMB client could lead to memory corruption, potentially impacting system stability or security. The NFS filehandle bounds checking flaw could also cause memory safety issues. Both vulnerabilities could be exploited to cause denial of service or other unintended behavior. However, no known exploits in the wild have been reported. The impact is rated moderate by Red Hat.

Summary

This Red Hat security advisory (RHSA-2025:17397) addresses two kernel vulnerabilities in Red Hat Enterprise Linux 8. The first vulnerability (CVE-2025-38527) is a use-after-free in the SMB client code within the cifs_oplock_break function. The second vulnerability (CVE-2025-39730) involves improper filehandle bounds checking in the nfs_fh_to_dentry() function. Both issues could lead to memory corruption or other stability problems in the kernel. The advisory provides updated kernel packages that fix these flaws. A system reboot is required to apply the fixes. The advisory affects multiple Red Hat Enterprise Linux 8 variants and architectures. No CVSS scores are included, but Red Hat rates the impact as moderate.

CWE-825Expired Pointer Dereference (opens in a new tab)
Base weakness
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
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-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
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)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Jun 2026, 22:28 UTC

WeaknessesCWE-825, CWE-125

Technical details

References

Community reviews

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