VulnerabilityPublished 2 Nov 2026

CVE-2026-99224: Linux kernel · keys: Protect the type name while describing a key

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.0 High · fixed in dea367df18e3a4faac393e3a4e818ee03af89b19 : patch Linux kernel soon.

Data as of 2 Nov 2026, 16:31 UTC

CVSS 3.1 base score

7.0High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (Linux)	CVSS 3.1	7.0

Patch: Available – fixed in dea367df18e3a4faac393e3a4e818ee03af89b19, dddd3a1ab7d12ee163477918ff6eb943361db4fe, a49e6c9a1a5b3457c946a8efb616ce13b4ca8194 +5

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Local
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 2 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < dea367df18e3a4faac393e3a4e818ee03af89b19	Fixed in dea367df18e3a4faac393e3a4e818ee03af89b19
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < dddd3a1ab7d12ee163477918ff6eb943361db4fe	Fixed in dddd3a1ab7d12ee163477918ff6eb943361db4fe
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < a49e6c9a1a5b3457c946a8efb616ce13b4ca8194	Fixed in a49e6c9a1a5b3457c946a8efb616ce13b4ca8194
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 916667df7695366f23cfaf365b5840b228cc4b2e	Fixed in 916667df7695366f23cfaf365b5840b228cc4b2e
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 0461bc8f91116aae4a020e15f4e1c1fd535ab35e	Fixed in 0461bc8f91116aae4a020e15f4e1c1fd535ab35e
LinuxLinux	Affected ≥ aa9d4437893f7e015ce5b6d6c443a9ba92c8a2e7, < 19c4de819e52b7f606468fbfe4fcef4e812e2777	Fixed in 19c4de819e52b7f606468fbfe4fcef4e812e2777

AI-suggested

A fix is available and has been applied in specific Linux kernel commits. Users and administrators should update to a fixed kernel version that includes the patches identified by the provided commit hashes. No additional mitigation is required once the kernel is updated. If updating is not immediately possible, avoiding use of the affected key description functionality or unloading the AF_RXRPC module during key description operations may reduce risk, but updating is strongly recommended.

Description

CVE-2026-99224 is a high-severity vulnerability in the Linux kernel affecting key description handling. The flaw arises because the key type's name is not properly protected during formatting in keyctl_describe_key(), leading to a use-after-free scenario when a module providing the key type is unloaded concurrently. This can cause a kernel page fault due to accessing freed memory. The issue is fixed by holding the key semaphore during formatting to prevent concurrent retirement of the key type module.

Impact

Exploitation of this vulnerability can cause a kernel page fault (BUG) due to use-after-free of the key type name string. This can lead to kernel crashes and potential denial of service. The CVSS 3.1 score is 7.0 (High), reflecting local attack vector with high impact on confidentiality, integrity, and availability. The vulnerability requires local privileges with low complexity and no user interaction.

Summary

The vulnerability in the Linux kernel involves the keyctl_describe_key() function, which describes a key by formatting its type name. The function saves the key type's name pointer and passes it to kasprintf() without holding the key semaphore (key->sem). kasprintf() performs two formatting passes with a memory allocation in between. If the AF_RXRPC module is loaded and a task with View permission triggers key description while the module is being unloaded, a race condition occurs: the module unregisters the key type and frees its name while the formatter is delayed between passes. This leads to the formatter accessing freed memory, causing a kernel page fault. The fix involves holding key->sem for reading across the entire kasprintf() call, preventing the key type from being retired during formatting. The semaphore is released immediately after kasprintf(), including on allocation failure, ensuring safe access to the key type name.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Nov 2026, 16:31 UTC

Technical details

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