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NVD / CVE Program· CNA Linux

CVE-2026-64479: ALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.18% (FIRST EPSS).
  • Fixed version: Linux Linux 435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4, 651ba82fe2a144bc7356d940bfd235c3810b0549, 6ded42615fa1f4949925afd0a8a9e1ab3bf96202.

Low priority for now. Upgrade to Linux Linux 435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4, 651ba82fe2a144bc7356d940bfd235c3810b0549, 6ded42615fa1f4949925afd0a8a9e1ab3bf96202 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: Fix uninitialised heap leak in snd_seq_event_dup() snd_seq_event_dup() copies an incoming event into a pool cell and, in the UMP-enabled build, clears the trailing cell->ump.raw.extra word that the memcpy() did not cover. The guard deciding whether to clear it compares the copied size against sizeof(cell->event): memcpy(&cell->ump, event, size); if (size < sizeof(cell->event)) cell->ump.raw.extra = 0; For a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) == sizeof(cell->event), so the condition is false and the extra word keeps stale data. The cell pool is allocated with kvmalloc() (not zeroed) and cells are reused via a free list, so that word holds uninitialised heap or leftover event data. When such a cell is delivered to a UMP client (client->midi_version > 0) that set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it unconverted -- snd_seq_read() reads it out as the larger struct snd_seq_ump_event and copies the stale word to user space, a 4-byte kernel heap infoleak to an unprivileged /dev/snd/seq client. Compare against sizeof(cell->ump) instead, so the trailing word is zeroed for every event shorter than the UMP cell.

—No exploit Fix available
Published
Jul 25, 2026
Updated
Nov 6, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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

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Noroxi analysis

What does it mean in your environment?

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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

    • 6.5affected
    • 6389f2c135311c4ce7c08c3b29145c8f95aacf1f and later · before d7649aa11089a93ea2285c210397aa67e5800766affected · git
    • d7e2ce72833bb23a82b4201fbed7214cc04a4a8c and later · before a224c84e5d3d35708c082c84ad12d81d90762195affected · git
    • 46397622a3fa8372b8fda0f04b33d16923b03b1b and later · before ea672a9f6cc38f06fe69dd2c257ef8a3d4db179aaffected · git
    • 46397622a3fa8372b8fda0f04b33d16923b03b1b and later · before fb1aa5082847b98f44f9c6272aee9d0dca9244f0affected · git
    • 46397622a3fa8372b8fda0f04b33d16923b03b1b and later · before 651ba82fe2a144bc7356d940bfd235c3810b0549affected · git
    • 46397622a3fa8372b8fda0f04b33d16923b03b1b and later · before 6ded42615fa1f4949925afd0a8a9e1ab3bf96202affected · git
    • 46397622a3fa8372b8fda0f04b33d16923b03b1b and later · before 435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4affected · git
    • before 6.5not affected · semver
    • 6.6.145 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:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.96-16.12.96-1
Debian:14linuxbefore 7.1.4-17.1.4-1

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-2026-64477Jul 25, 2026 · x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled
    0Monitor
  • ← EarlierCVE-2026-64478Jul 25, 2026 · ALSA: usb-audio: avoid kobject path lookup in DualSense match
    0Monitor
  • Later →CVE-2026-64480Jul 25, 2026 · ALSA: ice1712: check snd_ctl_new1() return value
    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 Linux435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4Vendor (CNA)
Linux Linux651ba82fe2a144bc7356d940bfd235c3810b0549Vendor (CNA)
Linux Linux6ded42615fa1f4949925afd0a8a9e1ab3bf96202Vendor (CNA)
Linux Linuxa224c84e5d3d35708c082c84ad12d81d90762195Vendor (CNA)
Linux Linuxd7649aa11089a93ea2285c210397aa67e5800766Vendor (CNA)
Linux Linuxea672a9f6cc38f06fe69dd2c257ef8a3d4db179aVendor (CNA)
Linux Linuxfb1aa5082847b98f44f9c6272aee9d0dca9244f0Vendor (CNA)
debian:linux6.12.96-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package 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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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 (6 more)

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

All records