A vulnerability in the Linux kernel ALSA dummy sequencer port causes a stack overread when handling UMP events. (CVE-2026-53241)
A vulnerability in the Linux kernel ALSA dummy sequencer port causes a stack overread when handling UMP events. The issue arises because the dummy client copies an incoming event into a smaller legacy-sized stack buffer while leaving the UMP flag set, leading to reading beyond the buffer during subscriber delivery. This has been fixed by using a union that accommodates the full UMP packet size, preserving correct event handling.
AI Analysis
Technical Summary
The Linux kernel ALSA dummy sequencer port had a vulnerability where UMP events were copied into a stack temporary sized for legacy events, which are smaller. Because the UMP flag remained set, subsequent processing used the larger UMP event size to copy data from this smaller buffer, causing a stack overread. The fix involves using a union that can store the full UMP event size and copying the full packet size before rewriting routing fields, thus preventing the overread while maintaining legacy event handling.
Potential Impact
This vulnerability results in a stack overread, which can cause a denial of service (crash) of the affected system. There is no indication of confidentiality or integrity impact. The attack vector requires local access with low privileges and no user interaction. The scope is unchanged, meaning the vulnerability does not affect other components beyond the ALSA dummy sequencer port.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix link is provided, users should monitor Linux kernel updates for a fix addressing this ALSA dummy sequencer UMP event stack overread vulnerability.
A vulnerability in the Linux kernel ALSA dummy sequencer port causes a stack overread when handling UMP events. (CVE-2026-53241)
Description
A vulnerability in the Linux kernel ALSA dummy sequencer port causes a stack overread when handling UMP events. The issue arises because the dummy client copies an incoming event into a smaller legacy-sized stack buffer while leaving the UMP flag set, leading to reading beyond the buffer during subscriber delivery. This has been fixed by using a union that accommodates the full UMP packet size, preserving correct event handling.
CVSS v3.1
Score 5.5medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel ALSA dummy sequencer port had a vulnerability where UMP events were copied into a stack temporary sized for legacy events, which are smaller. Because the UMP flag remained set, subsequent processing used the larger UMP event size to copy data from this smaller buffer, causing a stack overread. The fix involves using a union that can store the full UMP event size and copying the full packet size before rewriting routing fields, thus preventing the overread while maintaining legacy event handling.
Potential Impact
This vulnerability results in a stack overread, which can cause a denial of service (crash) of the affected system. There is no indication of confidentiality or integrity impact. The attack vector requires local access with low privileges and no user interaction. The scope is unchanged, meaning the vulnerability does not affect other components beyond the ALSA dummy sequencer port.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix link is provided, users should monitor Linux kernel updates for a fix addressing this ALSA dummy sequencer UMP event stack overread vulnerability.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-jcg9-m46h-g922
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53241"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a4e4ee2c9d9e3dbe3289562
Added to database: 07/08/2026, 13:21:38 UTC
Last enriched: 07/08/2026, 13:37:22 UTC
Last updated: 07/31/2026, 19:24:50 UTC
Views: 13
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.