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NVD / CVE Program· CNA Linux

CVE-2026-74388: ALSA: seq: oss: Fix UAF at handling events with embedded SysEx data

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3e85e690e787fa42f35e1bd9d18a7979c201d165, 6dc781778b595be94c31395b2cb167f65145d91f, 7aad70cabd8f34cf11a9593fcd3f2ac3f5496943.

Low priority for now. Upgrade to Linux Linux 3e85e690e787fa42f35e1bd9d18a7979c201d165, 6dc781778b595be94c31395b2cb167f65145d91f, 7aad70cabd8f34cf11a9593fcd3f2ac3f5496943 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: oss: Fix UAF at handling events with embedded SysEx data The OSS sequencer processes the input MIDI bytes into a sequencer event to be dispatched later (in snd_seq_oss_midi_putc() called from snd_seq_oss_process_event()). When it's a SysEx data, the event record contains data.ext.ptr pointer to the original SysEx bytes, and the referred data is copied into the pool afterwards at dispatching. The problem is that, if the sequencer port gets closed concurrently before the dispatch, the OSS sequencer core also releases the resources (in snd_seq_oss_midi_check_exit_port()), while the pending event may hold a stale pointer, eventually leading to a UAF at a later dispatch. Fortunately, there is already a refcounting mechanism (snd_use_lock_t) for the OSS MIDI device access, and for addressing the issue above, we just need to extend the refcount until the event gets dispatched. This patch extends snd_seq_oss_process_event() to give back the refcount object, which is in turn released after calling the sequencer dispatcher with the given event in the caller side. According to the original report, KASAN report as below: KASAN slab-use-after-free in snd_seq_event_dup+0x40c/0x470 RIP: 0033:0x7f2cb66a6340 Read of size 6 Call trace: dump_stack_lvl+0x73/0xb0 (?:?) print_report+0xd1/0x650 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x1a7/0x340 (?:?) kasan_complete_mode_report_info+0x64/0x200 (?:?) kasan_report+0xf7/0x130 (?:?) snd_seq_event_dup+0x40c/0x470 (?:?) kasan_check_range+0x10c/0x1c0 (?:?) __asan_memcpy+0x27/0x70 (?:?) snd_seq_event_dup+0x9/0x470 (?:?) snd_seq_client_enqueue_event+0x139/0x240 (?:?) _raw_spin_unlock_irqrestore+0x4b/0x60 (?:?) snd_seq_kernel_client_enqueue+0x102/0x120 (?:?) snd_seq_oss_write+0x416/0x4e0 (?:?) apparmor_file_permission+0x20/0x30 (?:?) odev_write+0x3b/0x60 (?:?) vfs_write+0x1ce/0x850 (?:?) lock_release+0xc8/0x2a0 (?:?) __kasan_check_write+0x18/0x20 (?:?) __mutex_unlock_slowpath+0x129/0x510 (?:?) ksys_write+0xe1/0x180 (?:?) mutex_unlock+0x16/0x20 (?:?) odev_ioctl+0x65/0xc0 (?:?) __x64_sys_write+0x46/0x60 (?:?) x64_sys_call+0x7d/0x20d0 (?:?) do_syscall_64+0xc1/0x360 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-74388

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.12affected
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 3e85e690e787fa42f35e1bd9d18a7979c201d165affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before bc963e193b314f1441082e8b1ffe15eb255d0a44affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before e96824274239ae4cd2f7b712644441cdc72c81a3affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 6dc781778b595be94c31395b2cb167f65145d91faffected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 7aad70cabd8f34cf11a9593fcd3f2ac3f5496943affected · git
    • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 7c349b4f2a603202fb8c363bd2774a22ac2fddf3affected · git
    • before 2.6.12not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.115-26.12.115-2
Debian:14linuxbefore 7.1.5-17.1.5-1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-defaultbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-docsbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-ec2before 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-sourcebefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-symsbefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-tracebefore 3.0.101-108.223.13.0.101-108.223.1
SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREkernel-xenbefore 3.0.101-108.223.13.0.101-108.223.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-74386Aug 15, 2026 · nvmet-tcp: fix page fragment cache leak in error path
    0Monitor
  • ← EarlierCVE-2026-74387Aug 15, 2026 · ALSA: seq: midi: Serialize output teardown with event_input
    31Monitor
  • Later →CVE-2026-74389Aug 15, 2026 · RDMA/hns: Fix log flood after cmd_mbox failure
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux3e85e690e787fa42f35e1bd9d18a7979c201d165Vendor (CNA)
Linux Linux6dc781778b595be94c31395b2cb167f65145d91fVendor (CNA)
Linux Linux7aad70cabd8f34cf11a9593fcd3f2ac3f5496943Vendor (CNA)
Linux Linux7c349b4f2a603202fb8c363bd2774a22ac2fddf3Vendor (CNA)
Linux Linuxbc963e193b314f1441082e8b1ffe15eb255d0a44Vendor (CNA)
Linux Linuxe96824274239ae4cd2f7b712644441cdc72c81a3Vendor (CNA)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)
debian:linux7.1.5-1 · Debian:14Package registry (OSV)
suse:kernel-default3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-docs3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-ec23.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-source3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-syms3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-trace3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)
suse:kernel-xen3.0.101-108.223.1 · SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME COREPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records