Linux Kernel up to 6.18.13/6.19.3 check_pseudo_btf_id 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$5k-$25k0.00

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.18.13/6.19.3. Affected by this vulnerability is the function check_pseudo_btf_id. This manipulation causes use after free. This vulnerability appears as CVE-2026-45951. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.18.13/6.19.3 and classified as critical. Affected by this vulnerability is the function check_pseudo_btf_id. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a potential use-after-free of BTF object Refcounting in the check_pseudo_btf_id() function is incorrect: the __check_pseudo_btf_id() function might get called with a zero refcounted btf. Fix this, and patch related code accordingly. v3: rephrase a comment (AI) v2: fix a refcount leak introduced in v1 (AI)

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-45951 since 05/13/2026. The exploitation appears to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/16/2026).

Upgrading to version 6.18.14 or 6.19.4 eliminates this vulnerability. Applying the patch eac65c272f3b49021a843cba5107d63627395e0e/9ff46ffeecdb1802d6e26183177935b948a12e7f/ccd2d799ed4467c07f5ee18c2f5c59bcc990822c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

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: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
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: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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 6.18.14/6.19.4
Patch: eac65c272f3b49021a843cba5107d63627395e0e/9ff46ffeecdb1802d6e26183177935b948a12e7f/ccd2d799ed4467c07f5ee18c2f5c59bcc990822c

Timelineinfo

05/13/2026 CVE reserved
05/27/2026 +14 days Advisory disclosed
05/27/2026 +0 days VulDB entry created
06/16/2026 +20 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-45951 (🔒)
GCVE (CVE): GCVE-0-2026-45951
GCVE (VulDB): GCVE-100-366223

Entryinfo

Created: 05/27/2026 17:16
Updated: 06/16/2026 08:23
Changes: 05/27/2026 17:16 (58), 06/16/2026 08:23 (11)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!