CASCACascade Atlas

Evidence dossier

CVE-2023-0266

Use after free in SNDRV_CTL_IOCTL_ELEM in Linux Kernel

Exploited in the wild (CISA KEV since Mar 30, 2023). NVD reports CVSS 3.1 7.0. EPSS estimates 3.7% exploit likelihood as of Aug 27, 2026.

65.5–68.9Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A use after free vulnerability exists in the ALSA PCM package in the Linux Kernel. SNDRV_CTL_IOCTL_ELEM_{READ|WRITE}32 is missing locks that can be used in a use-after-free that can result in a priviledge escalation to gain ring0 access from the system user. We recommend upgrading past commit 56b88b50565cd8b946a2d00b0c83927b7ebb055e

State
PUBLISHED
Published
Jan 30, 2023
Updated
Oct 21, 2025
Evidence coverage
98%

Evidence chronology

What was known when

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  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    Google

    Record text: Use after free in SNDRV_CTL_IOCTL_ELEM in Linux Kernel

    Inspect raw assertion
    Field
    container
    Value
    Use after free in SNDRV_CTL_IOCTL_ELEM in Linux Kernel
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Linux Kernel Use-After-Free Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Linux Kernel Use-After-Free Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 3.7% probability · 88.92th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.037020000000; percentile 0.889220000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 30, 2023 · first observed Jul 19, 2026

Exploit likelihood3.70%

FIRST EPSS · score date Aug 27, 2026 · 88.9th percentile · first observed Aug 27, 2026

SeverityCVSS 7.0

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
GoogleOriginal assertion
Record text

Use after free in SNDRV_CTL_IOCTL_ELEM in Linux Kernel

Inspect raw assertion
Field
container
Value
Use after free in SNDRV_CTL_IOCTL_ELEM in Linux Kernel
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Linux Kernel Use-After-Free Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Linux Kernel Use-After-Free Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

3.7% probability · 88.92th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.037020000000; percentile 0.889220000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
7Underlying assertions
2Canonical products
7Target assertions
0Constraint assertions

Grouped from 2 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

3 scope groups

Google · source assertedLinuxLinux KernelDirect source scope
Affected: 4.14 to before 56b88b50565cd8b946a2d00b0c83927b7ebb055e (git comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "4.14", "lessThan": "56b88b50565cd8b946a2d00b0c83927b7ebb055e", "versionType": "git"}]
NVD CPE · OPERATING SYSTEMdebiandebian_linuxVulnerable target · 1 assertions
Version 10.0Canonical identity product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447eLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    07b237a9-69a3-4a9c-9da0-4e06bd37ae73
NVD CPE · OPERATING SYSTEMlinuxlinux_kernelVulnerable target · 6 assertions
Any version (unconstrained) (>= 4.14, < 4.14.303); Any version (unconstrained) (>= 4.15, < 4.19.270); Any version (unconstrained) (>= 4.20, < 5.4.229); Any version (unconstrained) (>= 5.11, < 5.15.88); Any version (unconstrained) (>= 5.16, < 6.1.6); Any version (unconstrained) (>= 5.5, < 5.10.163)Canonical identity product-0eda7a801761be4590f267cf319481c8c0aaa30546d99cc064edf77989ce05c9Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 3
    Logic
    OR
    Version bounds
    from including 5.5; through excluding 5.10.163
    Match ID
    d05d31fc-bd74-4f9e-b1d8-9ced62be6f65
  2. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 2
    Logic
    OR
    Version bounds
    from including 4.20; through excluding 5.4.229
    Match ID
    a0c0d95e-414a-445e-941b-3ef6a4d3a093
  3. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    from including 4.14; through excluding 4.14.303
    Match ID
    e245bc6c-44bd-47d1-a03d-9fe1f29bb25a
  4. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 4
    Logic
    OR
    Version bounds
    from including 5.11; through excluding 5.15.88
    Match ID
    d71b7395-3263-46de-9341-53c437b49adf
  5. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 4.15; through excluding 4.19.270
    Match ID
    ae8904a3-99be-4e49-9682-1f90a6373f4f
  6. cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 5
    Logic
    OR
    Version bounds
    from including 5.16; through excluding 6.1.6
    Match ID
    04212ac4-ff1e-4f38-8ae9-53e2a69a00dc

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-9c702362a97e8770255c53f324861f65f3209d35ce95f01842c69a458450f6fa · product-0eda7a801761be4590f267cf319481c8c0aaa30546d99cc064edf77989ce05c9

Source class
Nvd cpe vulnerable target
Assertions
6
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
05f425d4-3a53-465c-8633-7504360d4c0d616b3726-1822-4654-ba77-ccc3f6a99e32664ef621-86fb-446e-be32-151bbf1ffda57112289b-4318-4f39-8edb-23b650935b7c80bc89e1-cbae-4eb2-a4db-0600b2708037e5dd651a-af80-4f0e-be84-cd80a5bd7387
Mapping establishedEvidence supported

vendor-66ae8c5e06427f7450637d18322b0dc411c0b469d940341cf076a620d444fe3c · product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447e

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
7de6e058-77e9-4ae6-8445-435bc0e69a8b
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
90dfc27b-f23e-4e01-8183-0681c14d08c3

Assessments

CVSS by origin

7.0
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.9
cve-coordination@google.comCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:H
7.9
GoogleCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:H

Direct CVE/CNA normalized decisions

7.9Priority eligible

Google

CVSS 3.1 · Primary · Original assertion · rank 1

CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:H
Validation
Valid match
Recomputed
7.9
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.