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NVD / CVE Program· CNA Linux

CVE-2026-99271: ALSA: line6: Clear prev_fbuf on capture buffer release

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: 0.15% (FIRST EPSS).
  • Fixed version: Linux Linux 22c82f33ff0b68d37041adf1dea5533a5863cd31, 862d9268f40a6e10cef24eb226e738fb69ce8aa7, aa118c8f61d59387961d58ffae831c5259a9f222.

Low priority for now. Upgrade to Linux Linux 22c82f33ff0b68d37041adf1dea5533a5863cd31, 862d9268f40a6e10cef24eb226e738fb69ce8aa7, aa118c8f61d59387961d58ffae831c5259a9f222 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: line6: Clear prev_fbuf on capture buffer release A KASAN slab-use-after-free read was reported in submit_audio_out_urb() when generating an impulse test signal: BUG: KASAN: slab-use-after-free in create_impulse_test_signal sound/usb/line6/playback.c:76 [inline] BUG: KASAN: slab-use-after-free in submit_audio_out_urb+0x1848/0x1b20 sound/usb/line6/playback.c:249 Read of size 2 at addr ffff888008d74870 by task syz.2.3214/7785 Allocated by task 11: kmem_cache_alloc_noprof+0x2f0/0x390 mm/slub.c:4144 line6_buffer_acquire+0x1a1/0x220 sound/usb/line6/pcm.c:158 line6_pcm_acquire+0xb6/0x230 sound/usb/line6/pcm.c:329 line6_startup_work+0x3c/0x50 sound/usb/line6/driver.c:728 Freed by task 7785: kfree+0xf8/0x390 mm/slub.c:6566 line6_buffer_release sound/usb/line6/pcm.c:176 [inline] line6_buffer_release+0xa5/0xf0 sound/usb/line6/pcm.c:170 __line6_pcm_release sound/usb/line6/pcm.c:305 [inline] line6_pcm_release+0x5a/0x80 sound/usb/line6/pcm.c:313 snd_toneport_monitor_put+0x11b/0x190 sound/usb/line6/toneport.c:183 line6pcm->prev_fbuf points into the capture PCM stream buffer (line6pcm->in.buffer), which is updated during audio_in_callback() to feed rate synchronization, software monitoring, and impulse test signal generation on playback side. When all capture streams are closed, line6_buffer_release() frees pstr->buffer with kfree(). However, it does not clear line6pcm->prev_fbuf. If playback is subsequently started (e.g. via impulse test signal volume control snd_line6_impulse_volume_put()), submit_audio_out_urb() dereferences the stale pointer line6pcm->prev_fbuf under in.lock, resulting in a slab-use-after-free read. Clear prev_fbuf and prev_fsize in line6_buffer_release() when releasing the capture stream buffer under in.lock, ensuring that no stale buffer pointer can be accessed by submit_audio_out_urb().

—No exploit Fix available
Published
Nov 7, 2026
Updated
Nov 10, 2026
EPSS
0.1% · 4th 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%

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Noroxi analysis

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Affected systems

Is your version affected?

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—

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

    • 4.0affected
    • 63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74 and later · before d063975ed22cdc2cb609a9828e5f658448193606affected · git
    • 63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74 and later · before 862d9268f40a6e10cef24eb226e738fb69ce8aa7affected · git
    • 63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74 and later · before 22c82f33ff0b68d37041adf1dea5533a5863cd31affected · git
    • 63e20df1e5b2ef8d871ecbdb6c038d554ed1ca74 and later · before aa118c8f61d59387961d58ffae831c5259a9f222affected · git
    • before 4.0not affected · semver
    • 6.12.117 and later · up to and including 6.12.*not affected · semver
    • 6.18.61 and later · up to and including 6.18.*not affected · semver
    • 7.3.2 and later · up to and including 7.3.*not affected · semver
    • 7.4-rc1 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—

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-2026-100081Nov 6, 2026 · xen-netback: defer xenvif_mcast_addr_list_free()
    31Monitor
  • ← EarlierCVE-2026-100082Nov 6, 2026 · xen-blkback: Avoid UAF when reading I/O statistics
    0Monitor
  • Later →CVE-2026-99272Nov 7, 2026 · smb: client: validate the data area in SMB2_read()
    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 Linux22c82f33ff0b68d37041adf1dea5533a5863cd31Vendor (CNA)
Linux Linux862d9268f40a6e10cef24eb226e738fb69ce8aa7Vendor (CNA)
Linux Linuxaa118c8f61d59387961d58ffae831c5259a9f222Vendor (CNA)
Linux Linuxd063975ed22cdc2cb609a9828e5f658448193606Vendor (CNA)

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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 11, 2026+4 d
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

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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

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Change log

  1. Fix✗ → ✓
  2. Exploit maturity— → none

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References

Show all references (3 more)

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

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