Linux Kernel up to 6.18.39/7.1.4 ALSA Sequencer OSS snd_seq_oss_readq_clear race condition

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.
9.5	$0-$5k	0.32+

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.18.39/7.1.4. This impacts the function snd_seq_oss_readq_clear of the component ALSA Sequencer OSS. This manipulation causes race condition. The identification of this vulnerability is CVE-2026-80628. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.18.39/7.1.4. Affected by this vulnerability is the function snd_seq_oss_readq_clear of the component ALSA Sequencer OSS. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. 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: seq: oss: Serialize readq reset state with q->lock snd_seq_oss_readq_clear() resets qlen, head, and tail without q->lock even though the normal reader and producer paths serialize the same ring state under that spinlock. A reset can therefore race snd_seq_oss_readq_free() or snd_seq_oss_readq_put_event() and leave stale records in the queue, drop freshly queued ones, or report the wrong readiness after wakeup. KCSAN reports a data race between snd_seq_oss_readq_clear() and snd_seq_oss_readq_free(). Take q->lock while clearing the ring and resetting input_time. Factor the enqueue logic into a caller-locked helper so snd_seq_oss_readq_put_timestamp() updates its suppression state under the same lock instead of racing the reset path. The buggy scenario involves two paths, with each column showing the order within that path: reset path: locked readq updater: 1. snd_seq_oss_reset() or 1. A reader or callback producer release reaches takes q->lock on the same queue. snd_seq_oss_readq_clear(). 2. snd_seq_oss_readq_clear() 2. The updater tests or modifies resets qlen, head, tail, qlen, head, and tail. and input_time. 3. snd_seq_oss_readq_clear() 3. The updater completes its wakes sleepers on read-modify-write sequence. q->midi_sleep. 4. Without q->lock, the reset 4. The resulting ring state drives can overlap the locked later reads and readiness. update. KCSAN reports: BUG: KCSAN: data-race in snd_seq_oss_readq_clear / snd_seq_oss_readq_free write to 0xffff8881069fe608 of 4 bytes by task 120516 on cpu 0: snd_seq_oss_readq_free+0x6c/0x80 snd_seq_oss_read+0xcb/0x250 odev_read+0x38/0x60 vfs_read+0xff/0x600 ksys_read+0xb4/0x140 __x64_sys_read+0x46/0x60 do_syscall_64+0xbb/0x2f0 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8881069fe608 of 4 bytes by task 120517 on cpu 1: snd_seq_oss_readq_clear+0x1f/0x90 snd_seq_oss_reset+0xa7/0xf0 snd_seq_oss_ioctl+0x6f6/0x7e0 odev_ioctl+0x56/0xc0 __x64_sys_ioctl+0xd1/0x120 do_syscall_64+0xbb/0x2f0 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000001 -> 0x00000000

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-80628 since 08/26/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/28/2026).

Upgrading to version 6.18.40 or 7.1.5 eliminates this vulnerability. Applying the patch 287d506d4e0865918cec82bb1361f283a08c979b/43e10709b1ba288bcbabb9b9cb6e518b2a5d8506/49ce92d207820f588b0406add82f053decfbe5d9 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4

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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
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: Race condition
CWE: CWE-362
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 6.18.40/7.1.5
Patch: 287d506d4e0865918cec82bb1361f283a08c979b/43e10709b1ba288bcbabb9b9cb6e518b2a5d8506/49ce92d207820f588b0406add82f053decfbe5d9

Timelineinfo

08/26/2026 CVE reserved
08/28/2026 +2 days Advisory disclosed
08/28/2026 +0 days VulDB entry created
08/28/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80628 (🔒)
GCVE (CVE): GCVE-0-2026-80628
GCVE (VulDB): GCVE-100-396559

Entryinfo

Created: 08/28/2026 10:18
Changes: 08/28/2026 10:18 (59)
Complete: 🔍
Cache ID: 216::103

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Discussion

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