Linux Kernel up to 7.3.0 keys keyctl_describe_key use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.7$0-$5k0.80

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.3.0. Affected by this issue is the function keyctl_describe_key of the component keys. Such manipulation leads to use after free. This vulnerability is traded as CVE-2026-99224. An attack has to be approached locally. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.3.0. Affected by this issue is the function keyctl_describe_key of the component keys. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: keys: Protect the type name while describing a key keyctl_describe_key() must keep the key type's name alive until kasprintf() has consumed it. The retained key reference keeps the key and its description alive, but does not pin the module providing its type. The name is passed to kasprintf() without holding key->sem. kvasprintf() uses the saved name pointer in two formatting passes, with a GFP_KERNEL allocation between them. With AF_RXRPC=m, a task that passes View permission before type retirement can overlap a privileged module unload in this order: 1. KEYCTL_DESCRIBE looks up the key, saves key->type->name in the kasprintf() arguments and completes the first formatting pass. 2. While the formatter is delayed before its second pass, af_rxrpc_exit() calls unregister_key_type(), which removes the type from the registry and waits for key_gc_keytype(). 3. The collector takes key->sem for writing, retypes the retained key to key_type_dead and completes retirement. Unregistration and module exit return, allowing free_module() to release the type and name. 4. The formatter resumes its second pass and reads the saved name from released module storage, which can fault in string(). Hold key->sem for reading across kasprintf(). The collector then cannot retype the key or complete retirement until both formatting passes have finished. If retirement wins the lock first, formatting uses the core key_type_dead name instead. Release the semaphore immediately after kasprintf(), including on allocation failure, before copying to userspace. Oops report as below: BUG: unable to handle page fault for address: fffffbfff8054794 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:string+0x23f/0x470 Call Trace: vsnprintf+0x330/0x1110

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-99224 since 09/25/2026. The exploitation is known to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 11/02/2026).

Upgrading to version 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.60, 7.2.14 or 7.3.1 eliminates this vulnerability. Applying the patch 19c4de819e52b7f606468fbfe4fcef4e812e2777/a49e6c9a1a5b3457c946a8efb616ce13b4ca8194/916667df7695366f23cfaf365b5840b228cc4b2e/dddd3a1ab7d12ee163477918ff6eb943361db4fe/3c3cfd9e262afc9558c38f8cec57f09d10988546/6b613747f7ea309ada5b8d05b55398c338f7a968/dea367df18e3a4faac393e3a4e818ee03af89b19/0461bc8f91116aae4a020e15f4e1c1fd535ab35e is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.0
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.273/5.15.224/6.1.191/6.6.161/6.12.115/6.18.60/7.2.14/7.3.1
Patch: 19c4de819e52b7f606468fbfe4fcef4e812e2777/a49e6c9a1a5b3457c946a8efb616ce13b4ca8194/916667df7695366f23cfaf365b5840b228cc4b2e/dddd3a1ab7d12ee163477918ff6eb943361db4fe/3c3cfd9e262afc9558c38f8cec57f09d10988546/6b613747f7ea309ada5b8d05b55398c338f7a968/dea367df18e3a4faac393e3a4e818ee03af89b19/0461bc8f91116aae4a020e15f4e1c1fd535ab35e

Timelineinfo

09/25/2026 CVE reserved
11/02/2026 +38 days Advisory disclosed
11/02/2026 +0 days VulDB entry created
11/02/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CNA: Linux
CVE: CVE-2026-99224 (🔒)

GCVE (CVE): GCVE-0-2026-99224
GCVE (VulDB): GCVE-100-429914

Entryinfo

Created: 11/02/2026 17:26
Changes: 11/02/2026 17:26 (68)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

Interested in the pricing of exploits?

See the underground prices here!