Linux Kernel up to 6.19.3 SMC use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.6$5k-$25k0.00

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.19.3. Affected is an unknown function of the component SMC. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-46330. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.19.3 and classified as critical. This vulnerability affects an unknown function of the component SMC. 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. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Revert "net/smc: Introduce TCP ULP support" This reverts commit d7cd421da9da2cc7b4d25b8537f66db5c8331c40. As reported by Al Viro, the TCP ULP support for SMC is fundamentally broken. The implementation attempts to convert an active TCP socket into an SMC socket by modifying the underlying `struct file`, dentry, and inode in-place, which violates core VFS invariants that assume these structures are immutable for an open file, creating a risk of use after free errors and general system instability. Given the severity of this design flaw and the fact that cleaner alternatives (e.g., LD_PRELOAD, BPF) exist for legacy application transparency, the correct course of action is to remove this feature entirely.

The weakness was shared by Al Viro. The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-46330 since 05/13/2026. The exploitation appears to be easy. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 06/10/2026).

Upgrading to version 6.19.4 eliminates this vulnerability. Applying the patch 6c505d95c69e27dbf28fea29dc84d2498d69515c/df31a6b0a3057e66994ad6ccf5d95b9b9514f033 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.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1870). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

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

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: Partially

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

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.19.4
Patch: 6c505d95c69e27dbf28fea29dc84d2498d69515c/df31a6b0a3057e66994ad6ccf5d95b9b9514f033

Timelineinfo

05/13/2026 CVE reserved
06/09/2026 +27 days Advisory disclosed
06/09/2026 +0 days VulDB entry created
06/10/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Researcher: Al Viro
Status: Confirmed

CVE: CVE-2026-46330 (🔒)
GCVE (CVE): GCVE-0-2026-46330
GCVE (VulDB): GCVE-100-369544
CERT Bund: WID-SEC-2026-1870 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 06/09/2026 17:01
Updated: 06/10/2026 22:01
Changes: 06/09/2026 17:01 (59), 06/10/2026 22:01 (7)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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