Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5 BPF bpf_link_show_fdinfo 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.
8.7	$5k-$25k	0.00

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5. The impacted element is the function bpf_link_show_fdinfo of the component BPF. Such manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2026-90392. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.156/6.12.109/6.18.51/7.2.5. It has been rated as very critical. Affected by this issue is the function bpf_link_show_fdinfo of the component BPF. 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: bpf: Fix potential UAF when reading bpf link info In bpf_link_show_fdinfo and bpf_link_get_info_by_fd, link->prog is accessed without holding any locks. If the prog is concurrently replaced via bpf_link_update, the old prog can be freed, leading to a potential UAF issue. Fix this by accessing link->prog under RCU protection to safely fetch the pointer and guarantee its lifetime while reading its fields.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-90392 since 09/11/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 09/17/2026).

Upgrading to version 6.6.157, 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch a5c936ac904767fc1d943d40b0308bcb2ae2509b/d7d7208e2603b45724b684f4df73904fb347741e/85cf991c881e7198be32be05a9daa2625390c8b3/79347e42cfbc9e78872922e8f08a70609c9af82f/863f3ddd0b8ac65abfb50d3be0869268ac0e277b is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.156
• 6.12.109
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

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

Physical: No
Local: No
Remote: Yes

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

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.157/6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: a5c936ac904767fc1d943d40b0308bcb2ae2509b/d7d7208e2603b45724b684f4df73904fb347741e/85cf991c881e7198be32be05a9daa2625390c8b3/79347e42cfbc9e78872922e8f08a70609c9af82f/863f3ddd0b8ac65abfb50d3be0869268ac0e277b

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90392 (🔒)
GCVE (CVE): GCVE-0-2026-90392
GCVE (VulDB): GCVE-100-406952

Entryinfo

Created: 09/17/2026 22:13
Changes: 09/17/2026 22:13 (59)
Complete: 🔍
Cache ID: 216::103

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Discussion

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