VulnerabilityPublished 4 Dec 2025Updated 9 Sep 2026

CVE-2025-40232: Linux kernel · rv: Fully convert enabled_monitors to use list_head as iterator

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 6.17.0-1008.8~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Low

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.17.0-1008.8~24.04.1, 6.17.0-1008.8, 6.17.0-1007.7~24.04.1 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Dec 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 or the CVSS exploit maturity 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.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 25.10linux`pkg:deb/ubuntu/linux?arch=source&distro=questing`Other threats	Affected <6.17.0-8.8	Fixed in 6.17.0-8.8
Ubuntu 25.10linux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=questing`Other threats	Affected <6.17.0-1005.5	Fixed in 6.17.0-1005.5
Ubuntu 25.10linux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=questing`Other threats	Affected <6.17.0-1006.6	Fixed in 6.17.0-1006.6
Ubuntu 25.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questing`Other threats	Affected 6.17.0-1003.3 – 6.17.0-1017.17 10 affected builds	Fixed in–
Ubuntu 25.10linux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=questing`Other threats	Affected <6.17.0-1005.5	Fixed in 6.17.0-1005.5
Ubuntu 25.10linux-oracle`pkg:deb/ubuntu/linux-oracle?arch=source&distro=questing`Other threats	Affected <6.17.0-1005.5	Fixed in 6.17.0-1005.5

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

AI-suggested

A patch is available and should be applied by updating to the fixed kernel package versions provided by Ubuntu in advisories USN-7920-1 and USN-7920-2. After updating, a system reboot is required to activate the fixes. Due to an ABI change, all third-party kernel modules must be recompiled and reinstalled. Users should follow standard Ubuntu update procedures to ensure the system is protected.

Description

A vulnerability in the Linux kernel related to inconsistent iterator usage in enabled_monitors_seq_ops has been resolved. The issue involved treating an iterator inconsistently as different data types, causing wrong type casting and system crashes. This flaw was fixed by fully converting enabled_monitors to use list_head as the iterator, ensuring consistency and preventing crashes. The vulnerability affects multiple Linux kernel versions, particularly in the linux-hwe-edge and related packages. Ubuntu has released patches addressing this and other kernel security issues, requiring system updates and reboots. Due to an ABI change, recompilation of third-party kernel modules is necessary after updating. No known exploits are reported in the wild, and the severity is assessed as low.

Impact

The vulnerability causes system crashes due to wrong type casting in kernel iterator usage, potentially leading to denial of service. There is no evidence of privilege escalation or remote code execution. No known exploits are reported in the wild. The impact is limited to system stability and reliability.

Summary

The Linux kernel contained a vulnerability where callbacks in enabled_monitors_seq_ops treated the iterator inconsistently—some as struct rv_monitor * and others as struct list_head *. This caused incorrect type casting leading to system crashes. The fix involved converting all usage to struct list_head * as the iterator, aligning enabled_monitors with available_monitors for consistency. This vulnerability affects numerous specific kernel versions across linux-hwe-edge and related Ubuntu kernel packages. Ubuntu's security advisories USN-7920-1 and USN-7920-2 detail the fixes, which also address other kernel security issues in tracing infrastructure and Netfilter subsystems. The updates require rebooting and recompiling third-party kernel modules due to ABI changes. There are no known active exploits for this vulnerability.

References

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