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NVD / CVE Program· CNA Linux

CVE-2026-68200: ALSA: timer: don't re-enter an instance callback that is still running

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: 0.13% (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 1395327a96614885552bae5fbb650e6dd182d49b, 70d28bfcd6224eed75986b3b987b997e59643fa4, 996c24377eea4d4506b7c3ccbbf1e490440b5e0b.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1395327a96614885552bae5fbb650e6dd182d49b, 70d28bfcd6224eed75986b3b987b997e59643fa4, 996c24377eea4d4506b7c3ccbbf1e490440b5e0b 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: timer: don't re-enter an instance callback that is still running The userspace-driven timer (utimer) TRIGGER ioctl calls snd_timer_interrupt() directly with no serialization, so two threads triggering the same utimer can run snd_timer_interrupt() on one snd_timer concurrently. snd_timer_process_callbacks() drops timer->lock around each instance callback and marks the in-flight callback with the single SNDRV_TIMER_IFLG_CALLBACK bit; snd_timer_close_locked() waits on that bit to drain an in-flight callback before freeing the instance. The bit cannot represent two concurrent callbacks: when a second interrupt re-queues an instance whose callback is still running, both run at once, the first to finish clears the bit, and the close-path drain then frees the instance (and its callback_data) while the other callback is still live - a use-after-free reachable by any user able to open /dev/snd/timer, both via a user timer instance and via a sequencer queue timer bound to the utimer. snd_timer_interrupt() sets IFLG_CALLBACK before dropping timer->lock, so a concurrent interrupt already observes it under the lock. Skip re-queuing an instance (and its slaves) to the ack/sack list while its callback is in flight; the accumulated pticks are delivered on the next tick, so no event is lost.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Aug 10, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 2th percentile

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.

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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

    • 6.12affected
    • 37745918e0e7575bc40f38da93a99b9fa6406224 and later · before 996c24377eea4d4506b7c3ccbbf1e490440b5e0baffected · git
    • 37745918e0e7575bc40f38da93a99b9fa6406224 and later · before 1395327a96614885552bae5fbb650e6dd182d49baffected · git
    • 37745918e0e7575bc40f38da93a99b9fa6406224 and later · before c1078130a4cd7e738f4b73afe99b3e68cbfbf884affected · git
    • 37745918e0e7575bc40f38da93a99b9fa6406224 and later · before 70d28bfcd6224eed75986b3b987b997e59643fa4affected · git
    • before 6.12not affected · semver
    • 6.12.101 and later · up to and including 6.12.*not affected · semver
    • 6.18.42 and later · up to and including 6.18.*not affected · semver
    • 7.1.6 and later · up to and including 7.1.*not affected · semver
    • 7.2 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
AlmaLinux:10kernelbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.56.1.el10_26.12.0-211.56.1.el10_2

+96

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-2026-68198Aug 10, 2026 · wifi: ath6kl: fix use-after-free in aggr_reset_state()
    35Monitor
  • ← EarlierCVE-2026-68199Aug 10, 2026 · wifi: ath6kl: fix OOB access from firmware ADDBA window size
    35Monitor
  • Later →CVE-2026-68201Aug 10, 2026 · ALSA: timer: drain a slave's callback before its master detaches it
    31Monitor

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 Linux1395327a96614885552bae5fbb650e6dd182d49bVendor (CNA)
Linux Linux70d28bfcd6224eed75986b3b987b997e59643fa4Vendor (CNA)
Linux Linux996c24377eea4d4506b7c3ccbbf1e490440b5e0bVendor (CNA)
Linux Linuxc1078130a4cd7e738f4b73afe99b3e68cbfbf884Vendor (CNA)
almalinux:kernel6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.56.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.12.101-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.101-1~deb12u1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-aarch640:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:6.12.0-211.56.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+1

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.

  • CVE-2026-720645 days apartnet: mana: Sync page pool RX frags for CPU
    39Monitor
  • CVE-2026-6397822 days apartnet/handshake: Drain pending requests at net namespace exit
    39Monitor
  • CVE-2026-683290 days apartiommu/amd: Wait for completion instead of returning early in iommu_completion_wait()
    35Monitor
  • CVE-2026-645616 days apartKVM: x86: Check for invalid/obsolete root *after* making MMU pages available
    35Monitor
  • CVE-2026-681380 days apartnet/sched: serialize qdisc_rtab_list against concurrent get/put
    31Monitor
  • CVE-2026-681430 days apartnet: slip: serialize receive against buffer reallocation
    31Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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.

ATT&CK techniques

—

Change log

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

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

References

Show all references (3 more)

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

All records