Linux Kernel up to 6.12.87/6.18.26/7.0.3/7.1-rc1 ALSA loopback_check_format streams[] use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.7$5k-$25k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.12.87/6.18.26/7.0.3/7.1-rc1 and classified as critical. This affects the function loopback_check_format of the component ALSA. This manipulation of the argument streams[] causes use after free. This vulnerability appears as CVE-2026-46090. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.87/6.18.26/7.0.3/7.1-rc1 and classified as critical. Affected by this vulnerability is the function loopback_check_format of the component ALSA. The manipulation of the argument streams[] 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: ALSA: aloop: Fix peer runtime UAF during format-change stop loopback_check_format() may stop the capture side when playback starts with parameters that no longer match a running capture stream. Commit 826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved the peer lookup under cable->lock, but the actual snd_pcm_stop() still runs after dropping that lock. A concurrent close can clear the capture entry from cable->streams[] and detach or free its runtime while the playback trigger path still holds a stale peer substream pointer. Keep a per-cable count of in-flight peer stops before dropping cable->lock, and make free_cable() wait for those stops before detaching the runtime. This preserves the existing behavior while making the peer runtime lifetime explicit.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-46090 since 05/13/2026. The exploitation appears to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 321697 (SUSE SLES16 Security Update : kernel (SUSE-SU-2026:22099-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.88, 6.18.27, 7.0.4 or 7.1-rc2 eliminates this vulnerability. Applying the patch 03f52a9c170431e8f10e156b9dc0dae80b3e9198/bdd9503c3d222d2735b56c7a8b4422ccf3de6e5c/5d45e34bf001344e2966dabca1897561bbc9e913/e5c33cdc6f402eab8abd36ecf436b22c9d3a8aff 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 databases at Tenable (321697) and EUVD (EUVD-2026-32473). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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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

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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: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 321697
Nessus Name: SUSE SLES16 Security Update : kernel (SUSE-SU-2026:22099-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.88/6.18.27/7.0.4/7.1-rc2
Patch: 03f52a9c170431e8f10e156b9dc0dae80b3e9198/bdd9503c3d222d2735b56c7a8b4422ccf3de6e5c/5d45e34bf001344e2966dabca1897561bbc9e913/e5c33cdc6f402eab8abd36ecf436b22c9d3a8aff

Timelineinfo

05/13/2026 CVE reserved
05/27/2026 +14 days Advisory disclosed
05/27/2026 +0 days VulDB entry created
06/21/2026 +25 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-46090 (🔒)
GCVE (CVE): GCVE-0-2026-46090
GCVE (VulDB): GCVE-100-366313
EUVD: 🔒

Entryinfo

Created: 05/27/2026 17:34
Updated: 06/21/2026 07:48
Changes: 05/27/2026 17:34 (60), 05/27/2026 18:16 (1), 06/21/2026 03:55 (11), 06/21/2026 07:48 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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